Sealant film for packaging material of power storage device, packaging material for power storage device, and power storage device

ABSTRACT

A sealant film has a structure made of a laminated body of two or more layers. The laminated body includes a first resin layer  7  containing 50 mass % or more of a random copolymer containing propylene and a copolymer component other than propylene as copolymer components, and a second resin layer  8  formed by a mixed resin containing a first elastomer-modified olefin based resin having a crystallization temperature of 105° C. or higher and a crystallization energy of 50 J/g or more, and a second elastomer-modified olefin based resin having a crystallization temperature is 85° C. or higher and a crystallization energy of 30 J/g or less. With this structure, when the inner pressure of a power storage device is excessively increased, breakage (separation) occurs inside the sealant layer, causing gas-releasing, which in turn can prevent bursting of the packaging material due to the inner pressure increase.

CROSS-REFERENCE TO THE RELATED APPLICATIONS

The present application claims priority to Japanese Patent ApplicationNo. 2015-191135 filed on Sep. 29, 2015 and Japanese Patent ApplicationNo. 2015-202967 filed on Oct. 14, 2015, the entire disclosure of each ofwhich is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

Technical Field

The present invention relates to a sealant film used to constitute apackaging material for a power storage device, a packaging material fora power storage device using the sealant film, and a power storagedevice constituted by using the packaging material.

In this specification and claims, the term “crystallization temperature”denotes a crystallization peak temperature measured by a differentialscanning calorimetry (DSC) in accordance with JIS K7121-1987, and theterm “crystallization energy” denotes a crystallization heat(crystallization energy) measured by a differential scanning calorimetry(DSC) in accordance with JIS K7122-1987.

Further, in this specification and claims, it is intended that the term“crystallization temperature” refers to the highest value amongcrystallization temperatures when there exist two or morecrystallization peaks and there exist two (Tcp1, Tcp2) or morecrystallization temperatures.

Further, in this specification and claims, it is intended that the term“crystallization energy” refers to a value of the highestcrystallization energy when there exists two or more crystallizationpeaks and there also exist two (ΔHc1, ΔHc2) or more crystallizationenergy.

Further, in this specification and claims, the term “aluminum” is usedto include the meaning of aluminum and its alloys.

Further, in this specification and claims, the term “polymer component”does not include neither of “first elastomer-modified olefin basedresin” and “second elastomer-modified olefin based resin”.

Further, in this specification and claims, although “olefin basedelastomer” and “styrene based elastomer” are defined, the elastomercontaining both olefin and styrene is defined to be classified(categorized) into (defined to belong to) the “styrene based elastomer”.

Description of the Related Art

The following description of related art sets forth the inventors'knowledge of related art and certain problems therein and should not beconstrued as an admission of knowledge in the prior art.

A lithium-ion secondary battery is widely used as an electric powersource for, e.g., a notebook computer, a video camera, a mobile phone,and an electric-powered vehicle. As the lithium-ion secondary battery, abattery structured such that a periphery of a battery body part (mainbody part including the positive electrode, the negative electrode, andthe electrolyte) is surrounded by a case is used. As the material forthe case (packaging material), for example, a material structured suchthat an outer layer made of a heat-resistant resin film, an aluminumfoil layer, and an inner layer made of a thermoplastic resin film areintegrally bonded in this order is well-known.

A power storage device is structured such that a power storage devicebody is sandwiched by a pair of packaging materials and the peripheraledge parts of the pair of packaging materials are fusion bonded (heatsealed) to be sealed.

In the meantime, in a lithium-ion secondary battery, etc., the batterybody part tends to generate a gas when excessively charged orexcessively raised in temperature. For this reason, in some cases, thegas is gradually accumulated in an inner space covered by the packagingmaterial, causing an increased inner pressure of the inside of thepackaging material. Since there is a concern that the increase in innerpressure causes bursting of the packaging material, a technology ofpreventing such bursting of the packaging material has been proposed.

For example, Patent Document 1 (Japanese Unexamined applicationpublication No. 2012-156404) discloses a power storage device equippedwith an explosion-proof function. The power storage device includes anelectrode laminated body in which sheet-shaped positive electrodes andnegative electrodes are laminated via separators. The electrodelaminated body is accommodated in a metal laminated film containertogether with electrolyte. The container is liquid-tightly sealed by aheat sealed portion formed by heat sealing the metal laminated film in astrip-shaped manner along the outer peripheral edge of the container.The power storage device is equipped with a perforating device includinga blade support fixedly secured with the outer peripheral edge part ofthe container pinched and a blade member supported by the blade supportand arranged at a center side position than the heat sealed portion ofthe container. The blade support is configured to move in the outerperipheral direction of the container by being pushed out by thecontainer expanded and deformed at the time of gas generation, so thatthe blade member is moved together with the blade support to cut thoughthe container.

Further, Patent Document 2 (Japanese Unexamined Application PublicationNo. 2012-156489) discloses an electric storage element. This electricstorage element is provided with an electric storage element body inwhich electrolyte is impregnated, a packaging member sealing theelectric storage element body, a first gas release mechanism arrangedinside the packaging member, and a second gas release mechanism arrangedoutside the packaging member. It is configured such that gas from theinner space of the packaging member accommodating the electric storageelement body sequentially passes through each of the gas releasemechanisms to thereby allow the gas release from the inner space to theouter space. Further, the electric storage element is provided with apressure adjustment device that prevents the intrusion of gas from theouter space to the inner space by each of the gas release mechanisms.Between the gas release mechanisms, a buffer space individuallypartitioned by each of the gas release mechanisms is formed.

However, as described in Patent Document 1, in the case of providing theperforating device including the blade support and the blade member,there are problems such that a new step for providing the perforatingdevice will be required, the production step becomes complicated, andthe productivity deteriorates. Further, it is required to provide astructural part, i.e., the perforating device, the cost increasescorrespondingly.

Further, as described in Patent Document 2, in the case of providing asafety valve mechanism (gas release mechanism, etc.) for releasing thegas generated in the packaging member to the outside of the packagingmember, there are problems such that a new step for providing the safetyvalve mechanism is required, and the productivity deteriorates. Further,it is required to provide a new structural part, i.e., a safety valvemechanism, the cost increases correspondingly.

The description herein of advantages and disadvantages of variousfeatures, embodiments, methods, and apparatus disclosed in otherpublications is in no way intended to limit the present disclosure. Forexample, certain features of the preferred described embodiments of thedisclosure may be capable of overcoming certain disadvantages and/orproviding certain advantages, such as, e.g., disadvantages and/oradvantages discussed herein, while retaining some or all of thefeatures, embodiments, methods, and apparatus disclosed therein.

SUMMARY OF THE INVENTION

Some embodiments in this disclosure have been developed in view of theabove-mentioned and/or other problems in the related art. Theembodiments in this disclosure can significantly improve upon existingmethods and/or apparatuses.

The present invention was made in view of the aforementioned technicalbackground, and aims to provide a sealant film for a packaging materialof a power storage device, a packaging material for a power storagedevice, and a power storage device, which is excellent in productivityand capable of reducing a production cost and securing an adequate sealstrength, and when an inner pressure of the power storage deviceincreases excessively, breakage (separation) occurs inside the sealantlayer to perform gas releasing to thereby prevent bursting of thepackaging material due to an inner pressure increase, even when thebroken point for bursting prevention is generated, continuous breakingwhich occurs from the broken point as a starting point hardlyprogresses, and whitening can be suppressed at the time of forming.

The other purposes and advantages of some embodiments of the presentdisclosure will be made apparent from the following preferredembodiments.

To attain the aforementioned objects, the present invention provides thefollowing means.

[1] A sealant film for a packaging material of a power storage device,including:

a laminated body of two or more layers,

wherein the laminated body includes

a first resin layer containing 50 mass % or more of a random copolymercontaining propylene and another copolymer component other thanpropylene as copolymer components, and

a second resin layer formed by a mixed resin containing a firstelastomer-modified olefin based resin having a crystallizationtemperature of 105° C. or higher and a crystallization energy of 50 J/gor more, and a second elastomer-modified olefin based resin having acrystallization temperature of 85° C. or higher and a crystallizationenergy of 30 J/g or less,

wherein the first elastomer-modified olefin based resin is made ofelastomer-modified homopolypropylene and/or elastomer-modified randomcopolymer,

wherein the second elastomer-modified olefin based resin is made ofelastomer-modified homopolypropylene and/or elastomer-modified randomcopolymer,

wherein the elastomer-modified random copolymer is an elastomer-modifiedproduct of a random copolymer containing propylene and another copolymercomponent other than propylene as copolymer components, and

wherein in the second resin layer, a total value of a content rate ofthe first elastomer-modified olefin based resin and a content rate ofthe second elastomer-modified olefin based resin is 50 mass % or more.

[2] The sealant film for a packaging material of a power storage deviceas recited in the aforementioned Item [1],

wherein in the second resin layer, the content rate of the secondelastomer-modified olefin based resin is 1 mass % to 50 mass %.

[3] The sealant film for a packaging material of a power storage deviceas recited in the aforementioned Item [1] or [2],

wherein the elastomer is an ethylene-propylene rubber.

[4] The sealant film for a packaging material of a power storage deviceas recited in any one of the aforementioned Items [1] to [3],

wherein the first resin layer contains an anti-blocking agent and a slipagent together with the random copolymer, and

wherein the second resin layer contains a slip agent together with thefirst elastomer-modified olefin based resin and the secondelastomer-modified olefin based resin.

[5] The sealant film for a packaging material of a power storage deviceas recited in any one of the aforementioned Items [1] to [4],

wherein the second elastomer-modified olefin based resin has two or morecrystallization peaks in a DSC measurement graph.

[6] The sealant film for a packaging material of a power storage deviceas recited in any one of the aforementioned Items [1] to [5],

wherein the sealant film includes only the first resin layer and thesecond resin layer laminated on one surface of the first resin layer.

[7] The sealant film for a packaging material of a power storage deviceas recited in any one of the aforementioned Items [1] to [5],

wherein the sealant film is a laminated body in which at least threelayers are laminated, the at least three layers including the secondresin layer, the first resin layer laminated on one of surfaces of thesecond resin layer, and a first resin layer laminated on the other ofsurfaces of the second resin layer.

[8] A packaging material for a power storage device, including:

a base material layer as an outer layer;

an inner sealant layer made of the sealant film as recited in any one ofthe aforementioned Items [1] to [7]; and

a metal foil layer arranged between the base material layer and theinner sealant layer,

wherein in the inner sealant layer, the first resin layer is arranged onan innermost layer side.

[9] A packaging case for a power storage device,

wherein the packaging case is made of a formed product of the packagingmaterial as recited in the aforementioned Item [8].

[10] A method for producing a packaging case for a power storage device,the method including deep drawing or stretch forming of the packagingmaterial for a power storage device as recited in the aforementionedItem [8].

[11] A power storage device includes

a power storage device main body, and

a packaging member made of the packaging material for a power storagedevice as recited in the aforementioned Item [8] and/or the packagingcase for a power storage device as recited in the aforementioned Item[9],

wherein the power storage device main body is packaged with thepackaging member.

[12] A sealant film for a packaging material of a power storage device,including:

a laminated body of two or more layers including

a first resin layer containing 50 mass % or more of a random copolymercontaining propylene and another copolymer component other thanpropylene as copolymer components,

a second resin layer formed by a composition containing a firstelastomer-modified olefin based resin having a crystallizationtemperature of 105° C. or higher and a crystallization energy of 50 J/gor more, and a polymer component,

wherein the first elastomer-modified olefin based resin is made ofelastomer-modified homopolypropylene and/or elastomer-modified randomcopolymer,

wherein the elastomer-modified random copolymer is an elastomer-modifiedproduct of a random copolymer containing propylene and another copolymercomponent other than propylene as copolymer components,

wherein in the second resin layer, a content rate of the firstelastomer-modified olefin based resin is 50 mass % or more, and

wherein the polymer component is at least one kind of polymer componentsselected from the group consisting of a random copolymer containingpropylene and another copolymer component other than propylene ascopolymer components, homopolypropylene, olefin based elastomer andstyrene based elastomer.

[13] A sealant film for a packaging material of a power storage device,including:

a laminated body of two or more layers,

wherein the laminated body includes

a first resin layer containing 50 mass % or more of a random copolymercontaining propylene and another copolymer component other thanpropylene as copolymer components,

a second resin layer formed by a composition containing a firstelastomer-modified olefin based resin having a crystallizationtemperature of 105° C. or higher and a crystallization energy of 50 J/gor more, a second elastomer-modified olefin based resin having acrystallization temperature of 85° C. or higher and a crystallizationenergy of 30 J/g or less, and a polymer component,

wherein the first elastomer-modified olefin based resin is made ofelastomer-modified homopolypropylene and/or elastomer-modified randomcopolymer,

wherein the second elastomer-modified olefin based resin is made ofelastomer-modified homopolypropylene and/or elastomer-modified randomcopolymer,

wherein the elastomer-modified random copolymer is an elastomer-modifiedproduct of a random copolymer containing propylene and another copolymercomponent other than propylene as copolymer components,

wherein in the second resin layer, a total value of a content rate ofthe first elastomer-modified olefin based resin and a content rate ofthe second elastomer-modified olefin based resin is 50 mass % or more,and

wherein the polymer component is at least one kind of polymer componentsselected from the group consisting of a random copolymer containingpropylene and another copolymer component other than propylene as acopolymer component, homopolypropylene, olefin based elastomer andstyrene based elastomer.

[14] The sealant film for a packaging material of a power storage deviceas recited in the aforementioned Item [13],

wherein in the second resin layer, a content rate of the secondelastomer-modified olefin based resin is 1 mass % to 50 mass %.

[15] The sealant film for a packaging material of a power storage deviceas recited in the aforementioned Item [13] or [14],

wherein the second elastomer-modified olefin based resin has two or morecrystallization peaks in a DSC measurement graph.

[16] The sealant film for a packaging material of a power storage deviceas recited in any one of the aforementioned Items [12] to [15],

wherein in the second resin layer, a content rate of the polymercomponent is 1 mass % or more and less than 50 mass %.

[17] The sealant film for a packaging material of a power storage deviceas recited in any one of the aforementioned Items [12] to [16],

wherein an elastomer in the elastomer-modified homopolypropylene is anethylene-propylene rubber, and

wherein an elastomer in the elastomer-modified random copolymer is anethylene-propylene rubber.

[18] The sealant film for a packaging material of a power storage deviceas recited in any one of the aforementioned Items [12] to [17],

wherein the first resin layer further contains an anti-blocking agentand a slip agent, and

wherein the second resin layer further contains a slip agent.

[19] The sealant film for a packaging material of a power storage deviceas recited in any one of the aforementioned Items [12] to [18],

wherein the sealant film includes only the first resin layer and thesecond resin layer laminated on one of surfaces of the first resinlayer.

[20] The sealant film for a packaging material of a power storage deviceas recited in any one of the aforementioned Items [12] to [18],

wherein the sealant film is a laminated body in which at least threelayers are laminated, the at least three layers including the secondresin layer, the first resin layer laminated on one of surfaces of thesecond resin layer, and a first resin layer laminated on the other ofsurfaces of the second resin layer.

[21] A packaging material for a power storage device, comprising:

a base material layer as an outer layer;

an inner sealant layer made of the sealant film as recited in any one ofthe aforementioned Items [12] to [20]; and

a metal foil layer arranged between the base material layer and theinner sealant layer,

wherein in the inner sealant layer, the first resin layer is arranged onan innermost layer side.

[22] A packaging case for a power storage device,

wherein the packaging case is made of a formed product of the packagingmaterial for a power storage device as recited in the aforementionedItem [21].

[23] A method for producing a packaging case for a power storage device,the method including deep drawing or stretch forming of the packagingmaterial for a power storage device as recited in the aforementionedItem [21].

[24] A power storage device including

a power storage device main body, and

a packaging member made of the packaging material for a power storagedevice as recited in the aforementioned Item [21] and/or the packagingcase for a power storage device as recited in the aforementioned Item[22],

wherein the power storage device main body is packaged with thepackaging member.

[25] A method for producing a sealant film resin composition for apackaging material of a power storage device, the method including

a preliminary melt-kneading step of obtaining a first melt-kneadedproduct by melt-kneading one, two or more kinds of elastomer componentsand one, two or more kinds of plastomer components, and

a step of obtaining a resin composition by mixing a first melt-kneadedproduct, a first elastomer-modified olefin based resin having acrystallization temperature of 105° C. or higher and a crystallizationenergy of 50 J/g or more, and a second elastomer-modified olefin basedresin having a crystallization temperature of 85° C. or higher and acrystallization energy of 30 J/g or less.

[26] The method for producing a sealant film resin composition for apackaging material of a power storage device as recited in theaforementioned Item [25],

wherein the elastomer component used in the preliminary melt-kneadingstep is one, two or more kinds of elastomer components selected from thegroup consisting of an olefin based elastomer, a styrene basedelastomer, and a second elastomer-modified olefin based resin having acrystallization temperature of 85° C. or higher and a crystallizationenergy of 30 J/g or less.

[27] The method for producing a sealant film resin composition for apackaging material of a power storage device as recited in theaforementioned Item [25] or [26],

wherein the plastomer component used in the preliminary melt-kneadingstep is one, two or more kinds of plastomer components selected from thegroup consisting of a random polypropylene, homopolypropylene, and afirst elastomer-modified olefin based resin having a crystallizationtemperature of 105° C. or higher and a crystallization energy of 50 J/gor more.

[28] The method for producing a sealant film resin composition for apackaging material of a power storage device as recited in theaforementioned Item [25],

wherein the elastomer component used in the preliminary melt-kneadingstep is a second elastomer-modified olefin based resin having acrystallization temperature of 85° C. or higher and a crystallizationenergy of 30 J/g or less, and

wherein the plastomer component used in the preliminary melt-kneadingstep contains a first elastomer-modified olefin based resin having acrystallization temperature of 105° C. or higher and a crystallizationenergy of 50 J/g or more, and further contains random polypropyleneand/or hommopolypropylene.

[29] A method for producing a sealant film resin composition for apackaging material of a power storage device, the method including

a preliminary melt-kneading step of obtaining a first melt-kneadedproduct by melt-kneading one, two or more kinds of elastomer componentsand one, two or more kinds of plastomer components, and

a step of obtaining a resin composition by mixing the first melt-kneadedproduct, and a first elastomer-modified olefin based resin having acrystallization temperature of 105° C. or higher and a crystallizationenergy of 50 J/g or more.

[30] The method for producing a sealant film resin composition for apackaging material of a power storage device as recited in theaforementioned Item [29],

wherein the elastomer component used in the preliminary melt-kneadingstep is one, two or more kinds of elastomer components selected from thegroup consisting of an olefin based elastomer, a styrene basedelastomer, and a second elastomer-modified olefin based resin having acrystallization temperature of 85° C. or higher and a crystallizationenergy of 30 J/g or less.

[31] The method for producing a sealant film resin composition for apackaging material of a power storage device as recited in theaforementioned Item [29] or [30],

wherein the plastomer component used in the preliminary melt-kneadingstep is one, two or more kinds of plastomer components selected from thegroup consisting of random polypropylene, homopolypropylene, and a firstelastomer-modified olefin based resin having a crystallizationtemperature of 105° C. or higher and a crystallization energy of 50 J/gor more.

[32] A method for producing a sealant film resin composition for apackaging material of a power storage device as recited in any one ofthe aforementioned Items [25] to [31], wherein in the preliminarymelt-kneading step, a mixing mass ratio of elastomer component/plastomercomponent is set within a range of 5/95 to 70/30.

In the invention as recited in the aforementioned Item [1], it isequipped with a first resin layer containing 50 mass % or more of arandom copolymer containing “propylene” and “another copolymer componentother than propylene” as copolymer components. Therefore, by arrangingthe first resin layer on the innermost layer side of the inner sealantlayer of the packaging material, sealing can be performed adequatelyeven at a relatively low temperature (adequate seal strength can besecured). Further, the second resin layer has a component obtained bycombining a first elastomer-modified olefin based resin having acrystallization temperature of 105° C. or higher and a crystallizationenergy of 50 J/g or more and a second elastomer-modified olefin basedresin having a crystallization temperature of 85° C. or higher and acrystallization energy of 30 J/g or less. Therefore, the compatibilityof elastomer component and olefin based resin is good, and thedispersiblity of elastomer component becomes good. With this, in thecase where the seal portion is broken due to the excessive increase ofthe inner pressure of the pair of packaging materials in which themutual inner sealant layers are heat-sealed joined, cohesive failureoccurs in the second resin layer (inside of the sealant layer), whichhardly causes breakage (separation) at the interface of the metal foillayer and the inner sealant layer. When a breakage (separation) forbursting prevention occurs, there is a merit that a breakage continuingfrom the broken point as a starting point hardly progresses.

Further, since compatibility of an interface of an elastomer phase andan olefin based resin phase is good, voids (cavities generated at aninside of the shaped product) unlikely occurs, and whitening can besuppressed at the time of shaping. Further, since the crystallizationtemperature of the first elastomer-modified olefin based resin is 105°C. or higher, the second resin layer hardly crushes at the time of theheat sealing, which in turn can secure insulation properties adequately.

Further, since it is not required to provide a new structural part (aperforating device or a gas release mechanism employed in a conventionaltechnology) separately to release gases outside, the production cost canbe reduced correspondingly, it becomes possible to attain furthercompactness, and the productivity is good.

In the invention as recited in the aforementioned Item [2], theaforementioned various effects can be secured sufficiently. Especially,at the time of the heat sealing, the second resin layer is more unlikelycrushed, and more sufficient insulation properties can be secured.

In the invention as recited in the aforementioned Item [3], theaforementioned various effects can be secured more assuredly.

In the invention as recited in the aforementioned Item [4], excellentslipping properties can be given to the surface of the packagingmaterial, which enables excellent shaping deeper in depth at the time ofshaping the packaging material and also enables adequate suppressing ofwhitening at the time of shaping the packaging material.

In the invention as recited in the aforementioned Item [5], theaforementioned various effects can be secured more adequately.

In the invention as recited in the aforementioned Items [6] and [7], theaforementioned various effects can be secured more assuredly.

In the invention as recited in the aforementioned Item [8], theproductivity is good, the cost can be suppressed, adequate seal strengthcan be secured, and when the inner pressure of the power storage deviceis increased excessively, cohesive failure occurs at the second resinlayer (inside of the sealant layer). Therefore, it is possible toprovide a packaging material for a power storage device that can preventbursting of the packaging material due to the increase of the innerpressure by performing gas-releasing, breakage continuing from thebroken point as a starting point unlikely progresses when the brokenpoint for bursting prevention is generated, and whitening can also besuppressed at the time of shaping.

In the invention as recited in the aforementioned Item [9], theproductivity is good, the cost can be suppressed, adequate seal strengthcan be secured, and when the inner pressure of the power storage deviceis increased excessively, cohesive failure occurs at the second resinlayer (inside of the sealant layer). Therefore, it is possible toprovide a packaging material for a power storage device that can preventbursting of the packaging material due to the increase of the innerpressure by performing gas-releasing, breakage continuing from thebroken point as a starting point unlikely progresses when the brokenpoint for bursting prevention is generated, and whitening can also besuppressed at the time of shaping.

In the invention as recited in the aforementioned Item [10], it ispossible to produce, with a good production efficiency, a packagingmaterial for a power storage device that can suppress the cost andsecure adequate seal strength, and also causes cohesive failure at thesecond resin layer (inside of the sealant layer) when the inner pressureof the power storage device is excessively increased to prevent burstingof the packaging material due to the increase of the inner pressure,breakage continuing from the broken point as a starting point unlikelyprogresses when the broken point for bursting prevention is generated,and whitening can also be suppressed at the time of shaping.

In the invention as recited in the aforementioned Item [11], it ispossible to produce a packaging material for a power storage device thatcan secure adequate seal strength for the packaging material, and alsocauses cohesive failure at the second resin layer (inside of the sealantlayer) when the inner pressure of the power storage device isexcessively increased to prevent bursting of the packaging material dueto the increase of the inner pressure, breakage continuing from thebroken point as a starting point unlikely progresses when the brokenpoint for bursting prevention is generated, and whitening can also besuppressed at the time of shaping.

In the invention as recited in the aforementioned Item [12], it isequipped with a first resin layer containing 50 mass % or more of arandom copolymer containing “propylene” and “another copolymer componentother than propylene” as copolymer components. Therefore, by arrangingthe first resin layer on the innermost layer side of the inner sealantlayer of the packaging material, sealing can be performed adequatelyeven at a relatively low temperature (adequate seal strength can besecured). Further, the second resin layer contains the firstelastomer-modified olefin based resin having a crystallizationtemperature of 105° C. or higher and a crystallization energy of 50 J/gor more. Therefore, the compatibility of the elastomer phase and theolefin based phase is good, and the dispersiblity of the elastomer phasebecomes good. With this, in cases where the seal portion is broken dueto the excessive increase of the inner pressure of the pair of packagingmaterials in which the mutual inner sealant layers are heat-sealedjoined, cohesive failure occurs in the second resin layer (inside of thesealant layer), which hardly causes breakage (separation) at theinterface of the metal foil layer and the inner sealant layer. When abreakage (separation) for bursting prevention occurs, there is a meritthat a breakage continuing from the broken point as a starting pointunlikely progresses.

Further, since compatibility of an interface of an elastomer phase andan olefin based resin phase is good, voids (cavities generated at aninside of the shaped product) unlikely occurs, and whitening can besuppressed at the time of shaping. Further, since the crystallizationtemperature of the first elastomer-modified olefin based resin is 105°C. or higher, the second resin layer is hardly crushed at the time ofthe heat sealing, which in turn can secure adequate insulationproperties.

Further, the second resin layer contains the specific polymer componenttogether with the first elastomer-modified olefin based resin having acrystallization temperature of 105° C. or higher and a crystallizationenergy of 50 J/g or more. Therefore, when the seal portion is broken dueto the excessive increase of the inner pressure, cohesive failureadequately occurs at the second resin layer (inside of the sealantlayer). When a breakage (separation) for bursting prevention occurs, aneffect that a breakage continuing from the broken point as a startingpoint unlikely progresses can be obtained, and whitening at the time ofshaping can be suppressed more adequately.

Further, since it is not required to provide a new structural part (aperforating device or a gas release mechanism employed in a conventionaltechnology) separately to release gases outside, the production cost canbe reduced correspondingly, it becomes possible to attain furthercompactness, and the productivity is good.

In the invention as recited in the aforementioned Item [13], it isequipped with a first resin layer containing 50 mass % or more of arandom copolymer containing “propylene” and “another copolymer componentother than propylene” as copolymer components. Therefore, by arrangingthe first resin layer on the innermost layer side of the inner sealantlayer of the packaging material, sealing can be performed adequatelyeven at a relatively low temperature (adequate seal strength can besecured). Further, the second resin layer has a component obtained bycombining a first elastomer-modified olefin based resin having acrystallization temperature of 105° C. or higher and a crystallizationenergy of 50 J/g or more and a second elastomer-modified olefin basedresin having a crystallization temperature of 85° C. or higher and acrystallization energy of 30 J/g or less. The compatibility of theelastomer phase and the olefin based phase is good, and thedispersiblity of the elastomer phase becomes good. With this, in caseswhere the seal portion is broken due to the excessive increase of theinner pressure of the pair of packaging materials in which the mutualinner sealant layers are heat-sealed joined, cohesive failure occurs inthe second resin layer (inside of the sealant layer), which hardlycauses breakage (separation) at the interface of the metal foil layerand the inner sealant layer. Therefore, when a breakage (separation) forbursting prevention occurs, there is a merit that a breakage continuingfrom the broken point as a starting point unlikely progresses.

Further, since compatibility of an interface of an elastomer phase andan olefin based resin phase is good, voids (cavities generated at aninside of the shaped product) unlikely occurs, and whitening can besuppressed at the time of shaping. Further, since the crystallizationtemperature of the first elastomer-modified olefin based resin is 105°C. or higher, the second resin layer is hardly crushed at the time ofthe heat sealing, which in turn can secure adequate insulationproperties.

Further, since the second resin layer further contains theaforementioned specific polymer component, when the seal portion isbroken due to the excessive increase of the inner pressure, cohesivefailure adequately occurs at the second resin layer (inside of thesealant layer). Therefore, when a breakage (separation) for burstingprevention occurs, an effect that a breakage continuing from the brokenpoint as a starting point unlikely progresses can be obtained, andwhitening at the time of shaping can be suppressed more adequately.

Further, since it is not required to provide a new structural part (aperforating device or a gas release mechanism employed in a conventionaltechnology) separately to release gases outside, the cost can be reducedcorrespondingly, it becomes possible to attain further compactness, andthe productivity is good.

In the invention as recited in the aforementioned Item [14], theaforementioned various effects can be secured sufficiently. Especially,at the time of the heat sealing, the second resin layer is more unlikelycrushed, and more sufficient insulation properties can be secured.

In the invention as recited in the aforementioned Item [15], theaforementioned various effects can be secured adequately.

In the invention as recited in the aforementioned Item [16], theaforementioned various effects can be secured more assuredly.

In the invention as recited in the aforementioned Item [17], theaforementioned various effects can be secured more assuredly.

In the invention as recited in the aforementioned Item [18], excellentslipping properties can be given to the surface of the packagingmaterial, which enables excellent shaping deeper in depth at the time ofshaping the packaging material and also enables adequate suppressing ofwhitening at the time of shaping the packaging material.

In the invention as recited in the aforementioned Items [19] and [20],the aforementioned various effects can be secured more assuredly.

In the invention as recited in the aforementioned Item [21], it ispossible to produce a packaging material for a power storage device thatis excellent in productivity, can suppress the cost and secure adequateseal strength, and also causes cohesive failure at the second resinlayer (inside of the sealant layer) when the inner pressure of the powerstorage device is excessively increased to prevent bursting of thepackaging material due to the increase of the inner pressure, breakagecontinuing from the broken point as a starting point unlikely progresseswhen the broken point for bursting prevention is generated, andwhitening can also be suppressed at the time of shaping.

In the invention as recited in the aforementioned Item [22], it ispossible to produce a packaging material for a power storage device thatis excellent in productivity, can suppress the cost and secure adequateseal strength, and also causes cohesive failure at the second resinlayer (inside of the sealant layer) when the inner pressure of the powerstorage device is excessively increased to prevent bursting of thepackaging material due to the increase of the inner pressure, breakagecontinuing from the broken point as a starting point unlikely progresseswhen the broken point for bursting prevention is generated, andwhitening can also be suppressed at the time of shaping.

In the invention as recited in the aforementioned Item [23], it ispossible to produce, with a good production efficiency, a packagingmaterial for a power storage device that can suppress the cost andsecure adequate seal strength, and also causes cohesive failure at thesecond resin layer (inside of the sealant layer) when the inner pressureof the power storage device is excessively increased to prevent burstingof the packaging material due to the increase of the inner pressure,breakage continuing from the broken point as a starting point unlikelyprogresses when the broken point for bursting prevention is generated,and whitening can also be suppressed at the time of shaping.

In the invention as recited in the aforementioned Item [24], it ispossible to produce a packaging material for a power storage device thatcan secure adequate seal strength for the packaging material, and alsocauses cohesive failure at the second resin layer (inside of the sealantlayer) when the inner pressure of the power storage device isexcessively increased to prevent bursting of the packaging material dueto the increase of the inner pressure, breakage continuing from thebroken point as a starting point unlikely progresses when the brokenpoint for bursting prevention is generated, and whitening can also besuppressed at the time of shaping.

In the present invention as recited in the aforementioned Item [25], inthe preliminary melt-kneading step, the elastomer component and theplastomer component are melt-knead to obtain the first melt-kneadedproduct, and in the first melt-kneaded product, the elastomer componentand the plastomer component are mixed mutually with a high degree ofdispersibility. Therefore, by mixing the first melt-kneaded product, thespecific first elastomer-modified olefin based resin (plastomer phase),and the specific second elastomer-modified olefin based resin (elastomerphase), the obtained resin composition is extremely excellent incompatibility of the interface of the elastomer phase and the plastomerphase (non-elastmer phase). Therefore, in the packaging material for apower storage device structured using the sealant film containing thesecond resin layer formed by the obtained resin composition, when thesealing portion is broken due to the excessive increase in the innerpressure of the pair of packaging material in which the mutual innersealant layers are heat-sealed joined, cohesive failure adequatelyoccurs at the second resin layer (inside of the sealant layer). Andbreakage (separation) at the interface of the metal foil layer and theinner sealant layer extremely hardly occurs. Therefore, when a breakage(separation) for bursting prevention occurs, an effect that a breakagecontinuing from the broken point as a starting point extremely unlikelyprogresses can be obtained, and whitening at the time of shaping can besuppressed more adequately.

In the invention as recited in the aforementioned Item [26], a resincomposition more excellent in compatibility of the interface of theelastomer phase and the plastomer phase (non-elastomer phase) can beobtained.

In the invention as recited in the aforementioned Item [27], a resincomposition further more excellent in compatibility of the interface ofthe elastomer phase and the plastomer phase (non-elastomer phase) can beobtained.

In the invention as recited in the aforementioned Item [28], a resincomposition more excellent in compatibility of the interface of theelastomer phase and the plastomer phase (non-elastomer phase) can beobtained.

In the present invention as recited in the aforementioned Item [29], inthe preliminary melt-kneading step, the elastomer component and theplastomer component are melt-kneaded to obtain the first melt-kneadedproduct, and in the first melt-kneaded product, the elastomer componentand the plastomer component are mixed mutually with a high degree ofdispersibility. Therefore, by mixing the first melt-kneaded product andthe specific first elastomer-modified olefin based resin (plastomerphase), the obtained resin composition is extremely excellent incompatibility of the interface of the elastomer phase and the plastomerphase (non-elastomer phase). Therefore, in the packaging material for apower storage device structured using the sealant film containing thesecond resin layer formed by the obtained resin composition, when theseal portion is broken due to the excessive increase in the innerpressure of the pair of packaging materials in which the inner sealantlayers are mutually heat-sealed joined, cohesive failure adequatelyoccurs at the second resin layer (inside of the sealant layer).Therefore, breakage (separation) at the interface of the metal foillayer and the inner sealant layer extremely hardly occurs. For thisreason, when a breakage (separation) for bursting prevention occurs, aneffect that a breakage continuing from the broken point as a startingpoint extremely unlikely progresses can be obtained, and whitening atthe time of shaping can be suppressed more adequately.

In the invention as recited in the aforementioned Item [30], a resincomposition more excellent in compatibility of the interface of theelastomer phase and the plastomer phase (non-elastomer phase) can beobtained.

In the invention as recited in the aforementioned Item [31], a resincomposition further more excellent in compatibility of the interface ofthe elastomer phase and the plastomer phase (non-elastomer phase) can beobtained.

In the invention as recited in the aforementioned Item [32], a resincomposition more excellent in compatibility of the interface of theelastomer phase and the plastomer phase (non-elastomer phase) can beobtained.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of the present disclosure are shown by way of example,and not limitation, in the accompanying figures.

FIG. 1 is a cross-sectional view of a packaging material for a powerstorage device according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of a packaging material for a powerstorage device according to another embodiment of the present invention.

FIG. 3 is a cross-sectional view of a power storage device according toone embodiment of the present invention.

FIG. 4 is a perspective view showing a packaging material (plane shape),a power storage device main body, and a packaging case(three-dimensionally shaped product) constituting the power storagedevice shown in FIG. 3 in a separated state before heat sealing.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

In the following paragraphs, some embodiments in the present disclosurewill be described by way of example and not limitation. It should beunderstood based on this disclosure that various other modifications canbe made by those in the art based on these illustrated embodiments.

One embodiment of a packaging material 1 for a power storage deviceaccording the present invention is shown in FIG. 1. This packagingmaterial 1 for a power storage device is used as, for example, apackaging material for a lithium-ion secondary battery. The packagingmaterial 1 for a power storage device may be used as a packagingmaterial as it is without being shaped, and also may be used as apackaging case 10 subjected to shaping, such as, e.g., deep drawing andstretch forming (see FIG. 4).

The packaging material 1 for a power storage device is structured suchthat a base material layer (outer layer) 2 is integrally laminated onone of surfaces of a metal foil layer 4 via a first adhesive agent layer5 and an inner sealant layer (inner layer) 3 is integrally laminated onthe other of surfaces of the metal foil layer 4 via a second adhesiveagent layer 6 (see FIGS. 1 and 2).

In the packaging material 1 shown in FIG. 1, the inner sealant layer(inner layer) 3 is structured only by a first resin layer 7 and a secondresin layer 8 laminated on one of surfaces of the first resin layer, andthe first resin layer 7 is arranged on the innermost layer side.

In the packaging material 1 shown in FIG. 2, the inner sealant layer(inner layer) 3 is a three-layer laminate structure including a secondresin layer 8, a first resin layer 7 laminated on one of surfaces of thesecond resin layer 8, and a first resin layer 7 laminated on the otherof surfaces of the second resin layer 8, and one of the first resinlayers 7 is arranged on the innermost layer side.

As the inner sealant layer (sealant film)(inner layer) 3, a sealant filmaccording to the first invention and a sealant film according to thesecond invention, which will be described later, is used. The detailstructure of the first resin layer and the second resin layer 8 will bedescribed later.

In the present invention, the inner sealant layer (inner layer) 3 givesexcellent chemical resistance also against highly corrosive electrolyte,etc., used in a lithium-ion secondary battery, etc., and plays a roll togive a heat sealing performance to a packaging material.

[Sealant Film for Packaging Material According to First Invention]

A sealant film for a packaging material according to the first inventionwill be described hereinafter. In the first invention, the inner sealantlayer (sealant film)(inner layer) 3 is made of a two or more layeredlaminated body including a first resin layer 7 containing 50 mass % ormore of a random copolymer containing “propylene” and “another copolymercomponent other than propylene” as copolymer components, and a secondresin layer formed by a mixed resin including a first elastomer-modifiedolefin based resin having a crystallization temperature (Tcp) of 105° C.or higher and a crystallization energy (ΔHc) of 50 J/g or more, and asecond elastomer-modified olefin based resin having a crystallizationtemperature (Tcp) of 85° C. or higher and a crystallization energy (ΔHc)of 30 J/g or less. It is preferable that the innermost layer of theinner sealant layer (inner layer) 3 be formed by the first resin layer7.

The first elastomer-modified olefin based resin (first polypropyleneblock copolymer) is made of elastomer-modified homopolypropylene and/orelastomer-modified random copolymer. The elastomer-modified randomcopolymer is an elastomer-modified product of a random copolymercontaining “propylene” and “another copolymer component other thanpropylene” as copolymer components. As the “another copolymer componentother than propylene”, although not specifically limited, it can beexemplified by, for example, olefin components, such as, e.g., ethylene,1-butene, 1-hexene, 1-pentene, and 4-methyl-1-pentene, as well asbutadiene, etc. As the elastomer, although not specifically limited, itis preferable to use EPR (ethylene-propylene rubber).

The second elastomer-modified olefin based resin (second polypropyleneblock copolymer) is made of elastomer-modified homopolypropylene and/orelastomer-modified random copolymer. The elastomer-modified randomcopolymer is an elastomer-modified product of a random copolymercontaining “propylene” and “another copolymer component other thanpropylene” as copolymer components. As the “another copolymer componentother than propylene”, although not specifically limited, it can beexemplified by, for example, an olefin component, such as, e.g.,ethylene, 1-butene, 1-hexene, 1-pentene, and 4-methyl-1-pentene, as wellas butadiene. As the elastomer, although not specifically limited, it ispreferable to use EPR (ethylene-propylene rubber).

The first resin layer 7 has a structure containing 50 mass % or more ofa random copolymer containing “propylene” and “another copolymercomponent other than propylene” as copolymer components. As the “anothercopolymer component other than propylene”, although not specificallylimited, it can be exemplified by, for example, butadiene, as well asolefin components, such as, e.g., ethylene, 1-butene, 1-hexene,1-pentene, and 4-methyl-1-pentene. When the content rate of the randomcopolymer is 50 mass % or more, an adequate heat seal strength can besecured. Among other things, it is preferable that the content rate ofthe random copolymer in the first resin layer 7 is set to 70 mass % ormore. It is preferable that the random copolymer (random copolymercontaining propylene and another copolymer component other thanpropylene as copolymer components) be a random copolymer having two ormore melting points. In this case, it is possible to obtain effects thatthe heat seal performance can be further improved by the randomcopolymer component having a low melting point (the heat seal strengthcan be further increased) and the first resin layer 7 is unlikelycrushed at the time of heat sealing by the random copolymer componenthaving a high melting point, and therefore more adequate insulationproperties can be secured.

The second resin layer 8 is formed by a mixed resin containing a firstelastomer-modified olefin based resin having a crystallizationtemperature (Tcp) of 105° C. or higher and having a crystallizationenergy (ΔHc) of 50 J/g or more and a second elastomer-modified olefinbased resin having a crystallization temperature (Tcp) of 85° C. orhigher and a crystallization energy (ΔHc) of 30 J/g or less. When thecrystallization temperature of the first elastomer-modified olefin basedresin is less than 105° C., whitening occurs markedly at the time ofshaping, and the second resin layer 8 tends to be crushed at the time ofheat sealing, which tends to become insufficient in insulation property(see Comparative Example 4).

Further, when the crystallization temperature of the secondelastomer-modified olefin based resin is less than 85° C., whiteningoccurs markedly at the time of shaping (see Comparative Example 5).Further, when the crystallization energy (ΔHc) of the firstelastomer-modified olefin based resin is less than 50 J/g, the cohesiondegree of the separation interface is medium, and therefore cohesivefailure of the separation interface hardly occurs. In other words,separation tends to occur at the interface of the metal foil layer andthe inner sealant layer at the time of separation, separation continuingfrom the separation point of the interface as a starting point readilyprogresses, and further the second layer 8 is readily crushed andtherefore the insulation properties tend to become insufficient (seeComparative Example 6).

Further, when the crystallization energy (ΔHc) of the secondelastomer-modified olefin based resin exceeds 30 J/g, whitening occursto some extent at the time of shaping, and the cohesion degree of theseparation interface is medium and therefore cohesive failure of theseparation interface hardly occurs. In other words, separation tends tooccur at the interface of the metal foil layer and the inner sealantlayer at the time of separation, and separation continuing from theseparation point of the interface as a starting point readily progresses(see Comparative Example 7).

Further, when the first elastomer-modified olefin based resin having acrystallization temperature (Tcp) of 105° C. or higher and acrystallization energy (ΔHc) of 50 J/g or more is not contained,whitening occurs to some extent at the time of shaping, the cohesiondegree of the separation interface is medium, the cohesion failure ofthe separation interface hardly occurs, i.e., separation tends to occurat the interface of the metal foil layer and the inner sealant layer atthe time of separation, and separation continuing from the separationpoint of the interface as a starting point readily progresses, andfurther the second resin layer 8 tends to be readily crushed and theinsulation property tends to become insufficient (see ComparativeExample 2).

Further, when the second elastomer-modified olefin based resin having acrystallization temperature (Tcp) of 85° C. or higher and acrystallization energy (ΔHc) of 30 J/g or less is not contained,whitening occurs markedly at the time of shaping, the cohesion degree ofthe separation interface is medium, the cohesion failure of theseparation interface hardly occurs, i.e., separation tends to readilyoccur at the interface of the metal foil layer and the inner sealantlayer at the time of separation, and there is a problem that separationcontinuing from the separation point of the interface as a startingpoint readily progresses (see Comparative Example 3).

Therefore, in the first invention, the second resin layer 8 is formed bya mixed resin containing a first elastomer-modified olefin based resinhaving a crystallization temperature (Tcp) of 105° C. or higher and acrystallization energy (ΔHc) of 50 J/g ore more and a secondelastomer-modified olefin based resin having a crystallizationtemperature (Tcp) of 85° C. or higher and a crystallization energy (ΔHc)of 30 J/g or less.

It is preferable that the crystallization temperature of the firstelastomer-modified olefin based resin be 105° C. or higher and 135° C.or lower. It is preferable that the crystallization energy of the firstelastomer-modified olefin based resin be 50 J/g or more and 75 J/g orless. It is preferable that the melting point of the secondelastomer-modified olefin based resin be 85° C. or higher and 125° C. orlower. It is preferable that the crystallization energy of the secondelastomer-modified olefin based resin be 5 J/g or more and 30 J/g orless, more preferably 10 J/g or more and 25 J/g or less, especiallypreferably 10 J/g or more and 20 J/g or less.

As to the first elastomer-modified olefin based resin and the secondelastomer-modified olefin based resin, the mode of the“elastomer-modified” may be graft polymerization or other modifiedmodes.

The first elastomer-modified olefin based resin and the secondelastomer-modified olefin based resin may be produced by, for example,the following reactor-made method. This is merely one example, and theyare not specifically limited by resins produced by such a productionmethod.

Initially, a Ziegler-Natta catalyst, a cocatalyst, and propylene aresupplied to a first reactor to polymerize homopolypropylene. Theobtained homopolypropylene is moved to a second reactor in a state inwhich unreacted propylene and Ziegler-Natta catalyst are contained.

In the second reactor, propylene is further added to polymerizehomopolypropylene. The obtained homopolypropylene is moved to a thirdreactor in a state in which unreacted propylene and Ziegler-Nattacatalyst are contained.

In the third reactor, by further adding ethylene and propylene topolymerize the ethylene-propylene rubber (EPR) in which ethylene andpropylene are copolymerized, the first elastomer-modified olefin basedresin or the second elastomer-modified olefin based resin can beproduced. The first elastomer-modified olefin based resin can beproduced by adding a solvent in a liquid phase, and the secondelastomer-modified olefin based resin can be produced by reacting in agas phase without using a solvent.

In the second resin layer 8, it is preferable that the content rate ofthe second elastomer-modified olefin based resin be 1 mass % to 50 mass%, more preferably 5 mass % to 30 mass %, especially preferably 10 mass% to 25 mass %.

In the second resin layer 8, it is preferable that the content rate ofthe first elastomer-modified olefin based resin be 99 mass % to 50 mass%, more preferably 95 mass % to 70 mass %, especially preferably 90 mass% to 75 mass %.

The second resin layer 8 is preferably in the form of a sea-islandstructure. With this sea-island structure, when the seal portion isbroken due to the excessive increase of the inner pressure, in thesecond resin layer 8, a breakage occurs at the interface of the olefinbased resin phase and the elastomer phase, causing cohesive failure atthe inside of the second resin layer 8. This hardly causes breakage(separation) at the interface of the metal foil layer and the innersealant layer. Therefore, when a breakage (separation) for burstingprevention occurs, an effect that a breakage continuing from the brokenpoint as a starting point unlikely progresses can be obtainedsufficiently. In the sea-island structure, a form that the elastomer(component) forms an island is preferred.

It is preferable that the second elastomer-modified olefin based resinhave two or more crystallization peaks in a DSC (differential scanningcalorimeter) measurement graph. When it has two crystallization peaks,it is preferable that the crystallization peak (crystallizationtemperature Tcp2) on the high temperature side be 90° C. or higher andthe crystallization peak (crystallization temperature Tcp1) on the lowtemperature side be 80° C. or lower. When it has three crystallizationpeaks, it is preferable that the crystallization peak (crystallizationtemperature) on the highest temperature side be 90° C. or higher and thecrystallization peak (crystallization temperature) on the lowesttemperature side be 80° C. or lower.

The integrated value (area) of the crystallization peak curve becomesthe crystallization energy (ΔHc). And in cases where there exist twocrystallization peaks in the DSC measurement graph, the integrated valueof the crystallization peak (Tcp1) curve lower in temperature is thecrystallization energy “ΔHc1”, and the integrated value of thecrystallization peak (Tcp2) curve higher in temperature is thecrystallization energy “ΔHc2” (see Tables 1 and 2).

[Sealant Film for Packaging Material According to Second Invention]

Next, a sealant film for a packaging material according to a secondinvention will be described hereinafter. In this second invention, theinner sealant layer (sealant film) (inner layer) 3 is made of a two ormore layered laminated body including a first resin layer 7, a secondresin layer 8. The first resin layer 7 contains 50 mass % or more of arandom copolymer containing “propylene” and “another copolymer componentother than propylene” as copolymer components.

In the sealant film for a packaging material according to the secondinvention, the second resin layer 8 is made of either the followingcompositions a) or b).

a) a composition containing a first elastomer-modified olefin basedresin having a crystallization temperature (Tcp) of 105° C. or higherand a crystallization energy (ΔHc) of 50 J/g or more, and a specificpolymer component

b) a composition containing a first elastomer-modified olefin basedresin having a crystallization temperature (Tcp) of 105° C. or higherand a crystallization energy (ΔHc) of 50 J/g or more, a secondelastomer-modified olefin based resin having a crystallizationtemperature (Tcp) of 85° C. or higher and a crystallization energy (ΔHc)of 30 J/g or less, and a specific polymer component

As the specific polymer component, at least one kind of polymercomponent selected from the group consisting of

a random copolymer containing “propylene” and “another copolymercomponent other than propylene” as copolymer components

homopolypropylene,

olefin based elastomer, and

styrene based elastomer.

As the “another copolymer component other than propylene” in the randomcopolymer, although not specifically limited, it can be exemplified by,for example, olefin component, such as, e.g., ethylene, 1-butene,1-hexene, 1-pentene, and 4-methyl-1-pentene, as well as butadiene. Asthe olefin based elastomer, for example, an ethylene-propylene rubber(EPR), an ethylene-1-butene rubber (EBR), an ethylene-propylene-dienerubber (EPDM), an isoprene rubber (IR), butadiene rubber (BR), a butylrubber (IIR), etc., can be exemplified. Further, as the styrene basedelastomer, for example, a styrene-ethylene-butylene-styrene copolymer(SEBS), a styrene-butadiene rubber (SBR), etc., can be exemplified.

In the second invention, in the second resin layer 8, even in the caseof either configuration a) or b), it contains the aforementionedspecific polymer component. Therefore, as compared with the system notcontaining the specific polymer component (Examples 1, 4, and 5), whenthe seal portion is broken due to the excessive increase of the innerpressure of the pair of packaging materials in which the mutual innersealant layers are heat-sealed joined, cohesive failure occursadequately in the second resin layer 8 (inside of the sealant layer)(which is apparent from the comparison of Examples 1, 4, and 5 andExamples 10 to 38), and whitening at the time of shaping can beadequately suppressed (which is apparent from the comparison of Examples1, 4, and 5 and Examples 10 to 38).

It is preferable that the innermost layer of the inner sealant layer(inner layer) 3 be formed by the first resin layer 7 (see FIGS. 1 and2).

It is preferable that the first elastomer-modified olefin based resin(first polypropylene block copolymer) be made of elastomer-modifiedhomopolypropylene and/or elastomer-modified random copolymer. Theelastomer-modified random copolymer is an elastomer-modified product ofa random copolymer containing “propylene” and “another copolymercomponent other than propylene” as copolymer components. As the “anothercopolymer component other than propylene”, although not specificallylimited, it can be exemplified by, for example, butadiene, other thanolefin component, such as, e.g., ethylene, 1-butene, 1-hexene,1-pentene, and 4-methyl-1-pentene. As the elastomer, although notspecifically limited, it is preferable to use EPR (ethylene-propylenerubber).

It is preferable that the second elastomer-modified olefin based resin(second polypropylene block copolymer) be made of elastomer-modifiedhomopolypropylene and/or elastomer-modified random copolymer. Theelastomer-modified random copolymer is an elastomer-modified product ofa random copolymer containing “propylene” and “another copolymercomponent other than propylene” as copolymer components. As the “anothercopolymer component other than propylene”, although not specificallylimited, it can be exemplified by, for example, butadiene, as well asolefin component, such as, e.g., ethylene, 1-butene, 1-hexene,1-pentene, and 4-methyl-1-pentene. As the elastomer, although notspecifically limited, it is preferable to use EPR (ethylene-propylenerubber).

The first resin layer 7 has a structure containing 50 mass % or more ofa random copolymer containing “propylene” and “another copolymercomponent other than propylene” as copolymer components. As the “anothercopolymer component other than propylene”, although not specificallylimited, it can be exemplified by, for example, butadiene, other thanolefin component, such as, e.g., ethylene, 1-butene, 1-hexene,1-pentene, and 4-methyl-1-pentene. When the content rate of the randomcopolymer is 50 mass % or more, an adequate heat seal strength can besecured. Among other things, it is preferable that the content rate ofthe random copolymer in the first resin layer 7 be set to 70 mass % ormore. It is preferable that the random copolymer (random copolymercontaining propylene and another copolymer component other thanpropylene as copolymer components) be a random copolymer having two ormore melting points. In this case, it is possible to obtain effects thatthe heat seal performance can be further improved by the randomcopolymer component having a low melting point (the heat seal strengthcan be further increased) and the first resin layer 7 is unlikelycrushed at the time of heat sealing by the random copolymer componenthaving a high melting point and therefore more adequate insulationproperties can be secured.

In the second invention, in cases where the second resin layer 8 is madeof either the following composition a) or b), when the crystallizationtemperature of the first elastomer-modified olefin based resin is lessthan 105° C., whitening occurs to some extent at the time of shaping,and the second resin layer 8 tends to be crushed at the time of heatsealing, which tends to become insufficient in insulation property (seeComparative Example 14). Further, when the crystallization energy (ΔHc)of the first elastomer-modified olefin based resin is less than 50 J/g,the cohesion degree of the separation interface is medium, and thereforecohesive failure of the separation interface hardly occurs. In otherwords, separation tends to occur at the interface of the metal foillayer and the inner sealant layer at the time of separation, separationcontinuing from the separation point of the interface as a startingpoint readily progresses, and further the second layer 8 is readilycrushed and therefore the insulation properties tend to becomeinsufficient (see Comparative Example 16).

In the second invention, in cases where the second resin layer 8 is madeof the aforementioned composition b), when the crystallizationtemperature of the second elastomer-modified olefin based resin is lessthan 85° C., whitening occurs to some extent at the time of shaping (seeComparative Example 15). Further, when the crystallization energy (ΔHc)of the second elastomer-modified olefin based resin exceeds 30 J/g,whitening occurs to some extent at the time of shaping (see ComparativeExample 17).

Further, when the second resin layer 8 does not contain the firstelastomer-modified olefin resin having a crystallization temperature(Tcp) of 105° C. or higher and a crystallization energy (ΔHc) of 50 J/gor more, whitening occurs to some extent at the time of shaping, thecohesion degree of the separation interface is medium, the cohesionfailure of the separation interface hardly occurs. In other words,separation tends to occur at the interface of the metal foil layer andthe inner sealant layer at the time of separation, separation continuingfrom the separation point of the interface as a starting point readilyprogresses, and further the second layer 8 is readily crushed andtherefore the insulation properties tend to become insufficient (seeComparative Example 13).

It is preferable that the crystallization temperature of the firstelastomer-modified olefin based resin be 105° C. or higher and 135° C.or lower. It is preferable that the crystallization energy of the firstelastomer-modified olefin based resin be 50 J/g or more and 75 J/g orless. It is preferable that the crystallization temperature of thesecond elastomer-modified olefin based resin be 85° C. or higher and125° C. or lower. It is preferable that the crystallization energy ofthe second elastomer-modified olefin based resin be 5 J/g or more and 30J/g or less, more preferably 10 J/g or more and 25 J/g or less,especially preferably 10 J/g or more and 20 J/g or less.

As to the first elastomer-modified olefin based resin and the secondelastomer-modified olefin based resin, the mode of the“elastomer-modified” may be graft polymerization or other modifiedmodes.

The first elastomer-modified olefin based resin and the secondelastomer-modified olefin based resin may be produced by, for example,the following reactor-made method. This is merely one example, and theyare not specifically limited by resins produced by such a productionmethod.

Initially, a Ziegler-Natta catalyst, a cocatalyst, propylene, andhydrogen are supplied to a first reactor to polymerizehomopolypropylene. The obtained homopolypropylene is moved to a secondreactor in a state in which unreacted propylene and Ziegler-Nattacatalyst are contained. In the second reactor, propylene and hydrogenare further added to polymerize homopolypropylene. The obtainedhomopolypropylene is moved to a third reactor in a state in whichunreacted propylene and Ziegler-Natta catalyst are contained. In thethird reactor, by further adding ethylene, propylene and hydrogen topolymerize the ethylene-propylene rubber (EPR) in which ethylene andpropylene are copolymerized, the first elastomer-modified olefin basedresin or the second elastomer-modified olefin based resin can beproduced. The first elastomer-modified olefin based resin can beproduced by adding a solvent in a liquid phase, and the secondelastomer-modified olefin based resin can be produced by reacting in agas phase without using a solvent.

In the second resin layer 8, it is preferable that the content rate ofthe first elastomer-modified olefin based resin be 99 mass % to 50 mass%, more preferably 95 mass % to 70 mass %, especially preferably 90 mass% to 75 mass %.

In the second resin layer 8, it is preferable that the content rate ofthe polymer component be 1 mass % or more and less than 50 mass %, morepreferably 5 mass % or more and 45 mass % or less, especially preferably10 mass % or more and 30 mass % or less.

In the second resin layer 8, in cases where the secondelastomer-modified olefin resin is contained, it is preferable that thecontent rate of the second elastomer-modified olefin based resin in thesecond resin layer 8 be 1 mass % to 50 mass %, more preferably 5 mass %to 30 mass %, especially preferably 10 mass % to 25 mass %.

The second resin layer 8 is preferably in the form of a sea-islandstructure. With this sea-island structure, when the seal portion isbroken due to the excessive increase of the inner pressure, in thesecond resin layer 8, a breakage occurs at the interface of the olefinbased resin phase and the elastomer phase, causing cohesive failure atthe inside of the second resin layer 8. Therefore, breakage (separation)at the interface of the metal foil layer and the inner sealant layeroccurs hardly. Therefore, when a breakage (separation) for burstingprevention occurs, an effect that a breakage continuing from the brokenpoint as a starting point unlikely progresses can be obtainedsufficiently. In the sea-island structure, a form that the elastomer(component) forms an island is preferred.

It is preferable that the second elastomer-modified olefin based resinhave two or more crystallization peaks in a DSC (differential scanningcalorimeter) measurement graph. When it has two crystallization peaks,it is preferable that the crystallization peak (crystallizationtemperature) on the highest temperature side be 90° C. or higher and thecrystallization peak (crystallization temperature) on the lowesttemperature side be 80° C. or lower. When it has three or morecrystallization peaks, it is preferable that the crystallization peak(crystallization temperature) on the highest temperature side be 90° C.or higher and the crystallization peak (crystallization temperature) onthe lowest temperature side be 80° C. or lower.

[Sealant Film for Packaging Material According to First Invention andSecond Invention]

In the sealant film of the first invention and the sealant film of thesecond invention, it is preferable that the first resin layer 7 bestructured not in the form of a sea-island structure. In such a case, itis possible to adequately suppress generation of voids (spaces) at theinterface of the olefin resin phase and the elastomer phase in the firstresin layer when the peripheral edge portion (including the flangeportion 29) is bent after sealing the power storage device main body 31by accommodating the power storage device main body 31 in the packagingmaterial 1 and/or the packaging case 10 and heat sealing the peripheraledge portion (including the flange portion 29. Therefore, there is amerit that the insulation property can be secured adequately.Especially, in cases where it is structured such that the first resinlayer 7 is arranged at the position adjacent to the metal foil layer 7,the aforementioned effect becomes significant.

In the sealant film of the first and second inventions, it is preferablethat the first resin layer 7 contains an anti-blocking agent and a slipagent together with the random copolymer. Further, it is preferable thatthe second resin layer 8 further contains a slip agent.

As the anti-blocking agent, although not specifically limited, forexample, silica, aluminum silicate, etc., can be exemplified. As theslip agent, although not specifically limited, for example, fatty acidamide such as erucicamide, stearic acid amide, and oleic amide, andwaxes such as crystalline wax and polyethylene wax can be exemplified.

In the sealant film of the first and second inventions, it is preferablethat the sealant film constituting the inner sealant layer (inner layer)3 be produced by a molding method, such as, e.g., a multilayer extrusionmolding, an inflation molding, and a T-die cast film molding.

In the sealant film of the first and second inventions, it is preferablethat the thickness of the inner sealant layer (inner layer) 3 be set to20 μm to 80 μm. By setting it to 20 μm or more, generation of pinholescan be prevented adequately, and by setting it to 80 μm or less, theresin used amount can be reduced, which in turn can attain the costreduction. Among other things, it is especially preferable that thethickness of the inner sealant layer (inner layer) 3 be set to 30 μm to50 μm.

In the sealant film of the first and second invention, when the innersealant layer (inner layer) 3 is a three-layer laminate structure formedby a second resin layer 8, a first resin layer 7 laminated on onesurface of the second resin layer 8, and a first resin layer 7 laminatedon the other surface of the second resin layer 8, it is preferable thatthe thickness ratio of the first resin layer 7/the second resin layer8/the first resin layer 7 be within a range of 0.5/9/0.5 to 3/4/3.

In the sealant film of the first and second invention, as a method forlaminating the sealant film constituting the inner sealant layer (innerlayer) 3 on the metal foil layer 4, although not specifically limited, adray lamination method, a sandwich lamination method (a method in whichan adhesive film of acid-modified polypropylene is extruded, theadhesive film is sand-laminated between the metal foil and the sealantfilm and heat laminated by heat rollers), etc., can be exemplified.

[Packaging Material for Power Storage Device According the PresentInvention]

In the packaging material for a power storage device according to thepresent invention, it is preferable that the base material layer (outerlayer) 2 be made of a heat-resistant resin layer. As the heat-resistantresin constituting the heat-resistant resin layer 2, a heat-resistantresin that does not melt at the heat seal temperature at the time ofheat sealing the packaging material is used. As the heat-resistantresin, it is preferable to use a heat-resistant resin having a meltingpoint higher than the melting point of the thermoplastic resinconstituting the inner sealant layer 3 by 10° C. or more, especiallypreferably a heat-resistant resin having a melting point higher than themelting point of the thermoplastic resin constituting the inner sealantlayer 3 by 20° C. or more.

As the heat-resistant resin layer (outer layer) 2, although notspecifically limited, for example, a polyamide film such as a nylonfilm, and a polyester film can be exemplified, and these stretched filmsare preferably used. Among other things, as the heat-resistant resinlayer 2, it is especially preferable to use a biaxially stretchedpolyamide film such as a biaxially stretched nylon film, a biaxiallystretched polybutylene terephthalate (PBT) film, a biaxially stretchedpolyethylene terephthalate (PET) film, or a biaxially stretchedpolyethylene naphthalate (PEN) film. As the nylon film, although notspecifically limited, for example, a 6 nylon film, a 6, 6 nylon film, aMXD nylon film can be exemplified. The heat-resistant resin layer 2 maybe a single layer, or a multi-layer made of, for example, polyesterfilm/polyamide film (e.g., multi-layer made of PET film/nylon film).

The thickness of the base material (outer layer) 2 is preferably 2 μm to50 μm. In the case of using a polyester film, the thickness ispreferably 2 μm to 50 μm, and in the case of using a nylon film, thethickness is preferably 7 μm to 50 μm. By setting it to theaforementioned preferable lower limit value or above, adequate strengthas a packaging material can be secured. By setting it to theaforementioned preferable upper limit value or below, the stress at thetime of shaping, such as stretch forming and drawing, can be reduced,which in turn can improve the formability.

In the packaging material for a power storage device according to thepresent invention, the metal foil layer 4 plays the role of giving a gasbarrier property of preventing invasion of oxygen and moisture into thepackaging material 1. As the metal foil layer 4, although notspecifically limited, for example, an aluminum foil, a SUS foil(stainless steel foil), a copper foil, etc., can be exemplified. Amongother things, it is preferable to use an aluminum foil or a SUS foil(stainless steel foil). The thickness of the metal foil layer 4 ispreferably 20 μm to 100 μm. By being 20 μm or more, pinhole generationcan be prevented at the time of rolling for producing a metal foil, andby being 100 μm or less, the stress at the time of shaping such asstretch forming and drawing can be reduced, which in turn can improvethe formability.

In the metal foil layer 4, it is preferable that at least inner sidesurface (surface on the second adhesive agent layer 6 side) is subjectedto a chemical conversion treatment. By being subjected to such achemical conversion treatment, corrosion of the metal foil surface bythe contents (electrolyte, etc., of a battery) can be preventedadequately. A metal foil is subjected to a chemical conversion treatmentby executing, for example, the following processing. That is, forexample, one of the following solutions 1) to 3) was applied onto thesurface of the metal foil to which a degreasing treatment was performed,and then dried to execute a chemical conversion treatment.

1) an aqueous solution of a mixture including

phosphoric acid,

chromic acid, and

at least one kind of compounds selected from the group consisting ofmetal salt of fluoride and non-metallic salt of fluoride

2) an aqueous solution of a mixture including

phosphoric acid,

at least one kind of resins selected from the group consisting of anacrylic based resin, a chitosan derivative resin, and a phenol basedresin, and

at least one kind of compounds selected from the group consisting ofchromic acid and chromium (III) salt

3) an aqueous solution of a mixture including

phosphoric acid,

at least one kind of resin selected from the group consisting of anacrylic based resin, a chitosan derivative resin, and a phenol basedresin,

at least one kind of compound selected from the group consisting ofchromic acid and chromium (III) salt, and

at least one kind of compound selected from the group including metalsalt of fluoride and non-metallic salt of fluoride

In the chemical conversion film, it is preferable that the chromiumdeposition amount (per one surface) be 0.1 mg/m² to 50 mg/m², especially2 mg/m² to 20 mg/m².

As the first adhesive agent layer 5, although not specifically limited,for example, a polyurethane adhesive layer, a polyester polyurethaneadhesive layer, and a polyether polyurethane adhesive layer can beexemplified. It is preferable that the thickness of the first adhesiveagent layer 5 be set to 1 μm to 5 μm. Among other things, from theviewpoint of the thinning and lightweighting of the packaging material1, it is especially preferable that the thickness of the first adhesiveagent layer 5 be set to 1 μm to 3 μm.

As the second adhesive agent layer 6, although not specifically limited,for example, a layer exemplified by the first adhesive agent layer 5 canbe used. It is preferable to use polyolefin-based adhesive less swellingby electrolyte. It is preferable that the thickness of the secondadhesive agent layer 6 be set to 1 μm to 5 μm. Among other things, fromthe viewpoint of the thinning and lightweighting of the packagingmaterial 1, it is especially preferable that the thickness of the secondadhesive agent layer 6 be set to 1 μm to 3 μm.

By shaping (deep drawing, stretch forming, etc.) the packaging material1 of the present invention, a packaging case (battery case, etc.) 10 canbe obtained (see FIG. 4). The packaging material 1 of the presentinvention can be used as it is without being subjected to shaping (seeFIG. 4).

One embodiment of a power storage device 30 structured by using thepackaging material 1 according the present invention is shown in FIG. 3.This power storage device 30 is a lithium-ion secondary battery. In thisEmbodiment, as shown in FIGS. 3 and 4, the packaging member 15 isconstituted by the packaging case 10 obtained by shaping the packagingmaterial 1 and the packaging material 1 in a plane shape. An approximaterectangular shaped power storage device main body (electrochemicaldevice, etc.) 31 is accommodated in the accommodation recess of thepackaging case 10 obtained by shaping the packaging material 1 of thepresent invention. On the power storage device main body 31, thepackaging material 1 of the present invention is arranged with its innersealant layer 3 side facing inward (downward) without being shaped. Andthe peripheral edge portion of the inner sealant layer 3 of the planarpackaging material 1 and the inner sealant layer 3 of the flange portion(sealing peripheral edge portion) 29 of the packaging case 10 areheat-sealed joined and sealed by heat sealing. Thus, the power storagedevice 30 of the present invention is structured (see FIGS. 3 and 4).The inner side surface of the accommodation recess of the packaging case10 is constituted by the inner sealant layer 3, and the outer surface ofthe accommodation recess is constituted by the base material layer(outer layer) 2 (see FIG. 4).

In FIG. 3, the reference numeral “39” denotes a heat-sealed portion inwhich the peripheral edge portion of the packaging material 1 and theflange portion (sealing peripheral edge portion) 29 of the packagingcase 10 are joined (welded). In the power storage device 30, a tip endportion of a tab lead connected to the power storage device main body 31is drawn to an outside of the packaging member 15, which is notillustrated.

As the power storage device main body 31, although not specificallylimited, for example, a battery body part, a capacitor main body, acondenser main body, etc., can be exemplified.

It is preferable that the width of the heat sealed portion 39 is set to0.5 mm or more. By setting it to 0.5 mm or more, sealing can beperformed assuredly. Among other things, it is preferable that the widthof the heat sealed portion 39 be set to 3 mm to 15 mm.

In the aforementioned Embodiment, the packaging member 15 is constitutedby the packaging case 10 obtained by shaping the packaging material 1and the planar packaging material 1 (see FIGS. 3 and 4). However, it isnot limited to such a combination, and for example, the packaging member15 may be structured by a pair of planar packaging materials 1, or maybe structured by a pair of packaging cases 10.

Next, preferable examples of the production method of a sealant filmresin composition (second resin layer resin composition) of a packagingmaterial for a power storage device will be described below.

In the first production method, one or two or more kinds of elastomercomponents and one or two or more kinds of plastomer components aremelt-kneaded to obtain a first melt-kneaded product (Preliminarymelt-kneading step).

Next, a first melt-kneaded product obtained in the preliminarymelt-kneading step and a first elastomer-modified olefin based resinhaving a crystallization temperature of 105° C. or higher and acrystallization energy of 50 J/g or more are mixed (other than a normalmixing, the mixing may be performed by melt-kneading, etc.) to obtain aresin composition. In this first production method, it is preferablethat the first elastomer-modified olefin based resin be made ofelastomer-modified homopolypropylene and/or elastomer-modified randomcopolymer. The elastomer-modified random copolymer is anelastomer-modified product of a random copolymer containing propyleneand another copolymer component other than propylene as copolymercomponents (the detail structure of the first elastomer-modified olefinbased resin is described above).

In the second production method, one or two or more kinds of elastomercomponents and one or two or more kinds of plastomer components aremelt-kneaded to obtain a first melt-kneaded product (Preliminarymelt-kneading step).

Next, a resin composition is obtained by mixing (other than a normalmixing, it can be mixed by melt-kneading, etc.) the first melt-kneadedproduct obtained by the preliminary melt-kneading step, a firstelastomer-modified olefin based resin having a crystallizationtemperature of 105° C. or higher and a crystallization energy of 50 J/gor more, and a second elastomer-modified olefin based resin having acrystallization temperature of 85° C. or higher and a crystallizationenergy of 30 J/g or less. In this second production method, it ispreferable that the first elastomer-modified olefin based resin be madeof elastomer-modified homopolypropylene and/or elastomer-modified randomcopolymer. It is preferable that the second elastomer-modified olefinbased resin be made of elastomer-modified homopolypropylene and/orelastomer-modified random copolymer. The elastomer-modified randomcopolymer is an elastomer-modified product of a random copolymercontaining propylene and another copolymer component other thanpropylene as copolymer components (the detail structure of the first andsecond elastomer-modified olefin based resins is described above).

In the first and second production methods, it is preferable that theelastomer component used in the preliminary melt-kneading step be one,two or more kinds of elastomer component selected from the groupconsisting of an olefin based elastomer, a styrene based elastomer, anda second elastomer-modified olefin based resin having a crystallizationtemperature of 85° C. or higher and a crystallization energy of 30 J/gor less. It is preferable that the second elastomer-modified olefinbased resin which can be used in the preliminary melt-kneading step bemade of elastomer-modified homopolypropylene and/or elastomer-modifiedrandom copolymer. The elastomer-modified random copolymer is anelastomer-modified product of a random copolymer containing propyleneand another copolymer component other than propylene as copolymercomponents (the detail structure of the second elastomer-modified olefinbased resin is described above). As the olefin based elastomer, forexample, an ethylene-propylene rubber (EPR), an ethylene-1-butene rubber(EBR), an ethylene-propylene-diene rubber (EPDM), an isoprene rubber(IR), a butadiene rubber (BR), a butyl rubber (IIR), etc., can beexemplified. Further, as the styrene based elastomer, for example, astyrene-ethylene-butylene-styrene copolymer (SEBS), a styrene-butadienerubber (SBR), etc., can be exemplified.

In the first and second production methods, it is preferable that theplastomer component used in the preliminary melt-kneading step is one,two or more kinds of plastomer components selected from the groupconsisting of random polypropylene, homopolypropylene, and a firstelastomer-modified olefin based resin having a crystallizationtemperature of 105° C. or higher and a crystallization energy of 50 J/gor more. It is preferable that the first elastomer-modified olefin basedresin which can be used in the preliminary melt-kneading step be made ofelastomer-modified homopolypropylene and/or elastomer-modified randomcopolymer. The elastomer-modified random copolymer is anelastomer-modified product of a random copolymer containing propyleneand another copolymer component other than propylene as copolymercomponents (the detail structure of the first elastomer-modified olefinbased resin is described above). The random polypropylene that can beused in the preliminary melt-kneading step is a random copolymercontaining “propylene” and “another copolymer component other thanpropylene” as copolymer components. As to the “another copolymercomponent other than propylene”, although not specifically limited, itcan be exemplified by, for example, butadiene, other than olefincomponent, such as, e.g., ethylene, 1-butene, 1-hexene, 1-pentene, and4-methyl-1-pentene.

In the preliminary melt-kneading step, it is preferable that a mixingmass ratio of elastomer component/plastomer component be set within arange of 5/95 to 70/30.

Further, in this first production method, it is preferable that a mixingmass ratio of the first melt-kneaded product/the firstelastomer-modified olefin based resin be set within a range of 5/95 to40/60.

Further, in this second production method, it is preferable that 95parts by weight to 50 parts by weight of the first elastomer-modifiedolefin based resin and 5 parts by weight to 50 parts by weight of thesecond elastomer-modified olefin based resin be mixed to 100 parts byweight of the first melt-kneaded product.

In the aforementioned production method, a material obtained by, e.g.,cutting the portion that will not be commercialized, such as, an earportion and an off-gauge portion generated when producing theaforementioned “sealant film for a packaging material of a power storagedevice” of the present invention (the two or more layer laminated bodyincluding the first resin layer 7 and the second resin layer 8), andthen crushing to obtain crushed materials, and further granulating thecrushed materials in a semi-molten state, can be used as the kneadingmaterial in the preliminary melt-kneading step.

EXAMPLES

Next, concrete examples of the present invention will be explained. Itshould be noted, however, that the present invention was notspecifically limited to these examples.

Example 1

On both surfaces of an aluminum foil 4 having a thickness of 35 μm, achemical conversion treatment solution including phosphoric acid,polyacrylic acid (acrylic based resin), chromium (III) salt compound,water, and alcohol is applied, and then dried at 180° C. to form achemical conversion film. The chromium deposition amount of thischemical conversion film was 10 mg/m² per one surface.

Next, on one surface of the chemical conversion treated aluminum foil 4,a biaxially stretched 6 nylon film 2 having a thickness of 15 μm was drylaminated (bonded) via a two-part curing type urethane based adhesive 5.

Next, a first resin layer 7 having a thickness of 4 μm and made ofethylene-propylene random copolymer, a second resin layer 8 having athickness of 22 μm (second resin layer 8 having a composition of 99 mass% of a first elastomer-modified olefin based resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g and 1 mass % of a second elastomer-modified olefin based resinhaving a crystallization temperature of 96° C. and a crystallizationenergy of 15 J/g), and a first resin layer 7 having a thickness of 4 μmmade of ethylene-propylene random copolymer were co-extruded using aT-die so that these layers are three-layered in this order. Thus, asealant film having a thickness of 30 μm in which these three layerswere laminated (first resin layer/second resin layer/first resin layer).Thereafter, one of surfaces of the first resin layer 7 of the sealantfilm 3 was overlapped on the other surface of the dry laminated aluminumfoil 4 by a two-part curing type maleic acid-modified polypropyleneadhesive agent 6, and pinched by and between a rubber nip roll and alamination roll heated to 100° C. to be press-bonded and dry laminated.Thereafter, by performing aging (heating) at 50° C. for 5 days, apackaging material 1 for a power storage device having a structure shownin FIG. 2 was obtained.

As the two-part curing type maleic acid-modified polypropylene adhesiveagent, using an adhesive agent solution in which 100 parts by weight ofmaleic acid-modified polypropylene (melting point 80° C., acid value 10mgKOH/g) as a base resin, 8 parts by weight of hexamethylenediisocyanate isocyanurate (NCO content rate: 20 mass %) as a curingagent, and further a solvent were mixed, the adhesive agent solution wasapplied on the other surface of the aluminum foil 4 so that the solidcontent applied amount became 2 g/m², and heated and dried, and thenoverlapped on one surfaces of the first resin layer 7 of the sealantfilm 3.

Example 2

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1 except for using,as a second resin layer 8, a second resin layer having a thickness of 22μm (second resin layer having a composition of 90 mass % of a firstelastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g and 10mass % of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g).

Comparative Example 1

A packaging material for a power storage device was obtained in the samemanner as in Example 2 except for using, as a resin constituting thefirst resin layer 7, a first elastomer-modified olefin based resinhaving a crystallization temperature of 114° C. and a crystallizationenergy of 54.2 J/g in place of ethylene-propylene random copolymer.

Comparative Example 2

A packaging material for a power storage device was obtained in the samemanner as in Example 1 except for using, as a second resin layer 8, asecond resin layer having a thickness of 22 μm (second resin layer madeof a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g).

Comparative Example 3

A packaging material for a power storage device was obtained in the samemanner as in Example 1 except for using, as a second resin layer 8, asecond resin layer having a thickness of 22 μm (second resin layer madeof a first elastomer-modified olefin based resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g).

Example 3

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1 except for using,as a second resin layer 8, a second rein layer having a thickness of 22μm (second resin layer having a composition of 90 mass % of a firstelastomer-modified olefin based resin having a crystallizationtemperature of 106° C. and a crystallization energy of 54.0 J/g and 10mass % of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g).

Comparative Example 4

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1 except for using,as a second resin layer 8, a second resin layer having a thickness of 22μm (second resin layer having a composition of 90 mass % of a firstelastomer-modified olefin based resin having a crystallizationtemperature of 96° C. and a crystallization energy of 53.0 J/g and 10mass % of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g).

Example 4

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1 except for using,as a second resin layer 8, a second resin layer having a thickness of 22μm (second resin layer having a composition of 90 mass % of a firstelastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g and 10mass % of a second elastomer-modified olefin based resin having acrystallization temperature of 88° C. and a crystallization energy of 14J/g).

Comparative Example 5

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1 except for using,as a second resin layer 8, a second resin layer having a thickness of 22μm (second resin layer having a composition of 90 mass % of a firstelastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g and 10mass % of a second elastomer-modified olefin based resin having acrystallization temperature of 83° C. and a crystallization energy of 10J/g).

Comparative Example 6

A packaging material for a power storage device structured was obtainedin the same manner as in Example 1 except for using, as a second resinlayer 8, a second resin layer having a thickness of 22 μm (second resinlayer having a composition of 90 mass % of a first elastomer-modifiedolefin based resin having a crystallization temperature of 106° C. and acrystallization energy of 45.5 J/g and 10 mass % of a secondelastomer-modified olefin based resin having a crystallizationtemperature of 96° C. and a crystallization energy of 15 J/g).

Example 5

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1 except for using,as a second resin layer 8, a second resin layer having a thickness of 22μm (second resin layer having a composition of 80 mass % of a firstelastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g and 20mass % of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g).

Example 6

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1 except for using,as a second resin layer 8, a second resin layer having a thickness of 22μm (second resin layer having a composition of 70 mass % of a firstelastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g and 30mass % of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g).

Example 7

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1 except for using,as a second resin layer 8, a second resin layer having a thickness of 22μm (second resin layer having a composition of 80 mass % of a firstelastomer-modified olefin based resin having a crystallizationtemperature of 117° C. and a crystallization energy of 61.2 J/g and 20mass % of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g).

Example 8

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1 except for using,as a second resin layer 8, a second resin layer having a thickness of 22μm (second resin layer having a composition of 70 mass % of a firstelastomer-modified olefin based resin having a crystallizationtemperature of 117° C. and a crystallization energy of 61.2 J/g and 30mass % of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g).

Comparative Example 7

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1 except for using,as a second resin layer 8, a second resin layer having a thickness of 22μm (second resin layer having a composition of 90 mass % of a firstelastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g and 10mass % of a second elastomer-modified olefin based resin having acrystallization temperature of 108° C. and a crystallization energy of40 J/g).

Comparative Example 8

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1 except for using,as a second resin layer 8, a second resin layer having a thickness of 22μm (second resin layer having a composition of 99 mass % of a firstelastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g and 1mass % of an EPR having a crystallization temperature of 56° C. and acrystallization energy of 11 J/g).

Comparative Example 9

A packaging material for a power storage device structured was obtainedin the same manner as in Example 1 except for using, as a second resinlayer 8, a second resin layer having a thickness of 22 μm (second resinlayer having a composition of 90 mass % of a first elastomer-modifiedolefin based resin having a crystallization temperature of 114° C. and acrystallization energy of 54.2 J/g and 10 mass % of an EPR having acrystallization temperature of 56° C. and a crystallization energy of 11J/g).

Comparative Example 10

A packaging material for a power storage device structured was obtainedin the same manner as in Example 1 except for using, as a second resinlayer 8, a second resin layer having a thickness of 22 μm (second resinlayer having a composition of 80 mass % of a first elastomer-modifiedolefin based resin having a crystallization temperature of 114° C. and acrystallization energy of 54.2 J/g and 20 mass % of an EPR having acrystallization temperature of 56° C. and a crystallization energy of 11J/g).

Comparative Example 11

A packaging material for a power storage device was obtained in the samemanner as in Example 1 except for using, as a second resin layer 8, asecond resin layer having a thickness of 22 μm (second resin layerhaving a composition of 70 mass % of a first elastomer-modified olefinbased resin having a crystallization temperature of 114° C. and acrystallization energy of 54.2 J/g and 30 mass % of an EPR having acrystallization temperature of 56° C. and a crystallization energy of 11J/g).

Example 9

On both surfaces of an aluminum foil 4 having a thickness of 35 μm, achemical conversion treatment solution including phosphoric acid,polyacrylic acid (acrylic based resin), chromium (III) salt compound,water, and alcohol was applied, and then dried at 180° C. to form achemical conversion film. The chromium deposition amount of thischemical conversion film was 10 mg/m² per one surface.

Next, on one surface of the chemical conversion treated aluminum foil 4,a biaxially stretched 6 nylon film 2 having a thickness of 15 μm was drylaminated (bonded) via a two-part curing type urethane based adhesive 5.

Next, a first resin layer 7 having a thickness of 8 μm and made ofethylene-propylene random copolymer, and a second resin layer 8 having athickness of 22 μm (second resin layer 8 having a composition of 90 mass% of a first elastomer-modified olefin based resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g and 10 mass % of a second elastomer-modified olefin based resinhaving a crystallization temperature of 96° C. and a crystallizationenergy of 15 J/g), were co-extruded using a T-die so that these layersare laminated. Thus, a sealant film having a thickness of 30 μm in whichthese two layers were laminated (first resin layer 7/second resin layer8). Thereafter, one of the first resin layer 7 surface of the sealantfilm 3 was overlapped on the other surface of the dry laminated aluminumfoil 4 by a two-part curing type maleic acid-modified polypropyleneadhesive agent 6, and pinched by and between a rubber nip roll and alamination roll heated to 100° C. to be press-bonded and dry laminated.Thereafter, by performing aging (heating) at 50° C. for 5 days, apackaging material 1 for a power storage device having a structure shownin FIG. 1 was obtained.

As the two-part curing type maleic acid-modified polypropylene adhesiveagent, using an adhesive agent solution in which 100 parts by weight ofmaleic acid-modified polypropylene (melting point 80° C., acid value 10mgKOH/g) as a base resin, 8 parts by weight of hexamethylenediisocyanate isocyanurate (NCO content rate: 20 mass %) as a curingagent, and further a solvent were mixed, the adhesive agent solution wasapplied on the other surface of the aluminum foil 4 so that the solidcontent applied amount became 2 g/m², and heated and dried, and thenoverlapped on one of surfaces of the first resin layer 7 of the sealantfilm 3.

TABLE 1 Second resin layer First elastomer-modified First resin olefinbased resin Second elastomer-modified olefin based resin layer ContentContent Tmp ΔHc Tcp rate ΔHc1 ΔHc2 ΔHc Tcp1 Tcp2 Tcp rate Type (° C.)Type (J/g) (° C.) (mass %) Type (J/g) (J/g) (J/g) (° C.) (° C.) (° C.)(mass %) Com. Ex 1 B-PP1X — B-PP1X 54.2 114 90 B-PP2X 1.7 15 — 72 96 —10 Com. Ex 2 r-PPA 144.152 — — — — B-PP2X 1.7 15 — 72 96 — 100 Com. Ex.3 r-PPA 144.152 B-PP1X 54.2 114 100 — — — — — — — — Ex. 1 r-PPA 144.152B-PP1X 54.2 114 99 B-PP2X 1.7 15 — 72 96 — 1 Ex. 2 r-PPA 144.152 B-PP1X54.2 114 90 B-PP2X 1.7 15 — 72 96 — 10 Ex. 3 r-PPA 144.152 B-PP1Z 54.0106 90 B-PP2X 1.7 15 — 72 96 — 10 Com. Ex. 4 r-PPA 144.152 B-PP1V 53.096 90 B-PP2X 1.7 15 — 72 96 — 10 Ex. 4 r-PPA 144.152 B-PP1X 54.2 114 90B-PP2Y — — 14 — — 88 10 Com. Ex. 5 r-PPA 144.152 B-PP1X 54.2 114 90B-PP2Z — — 10 — — 83 10 Com. Ex. 6 r-PPA 144.152 B-PP1W 45.5 106 90B-PP2X 1.7 15 — 72 96 — 10 Ex. 5 r-PPA 144.152 B-PP1X 54.2 114 80 B-PP2X1.7 15 — 72 96 — 20 Ex. 6 r-PPA 144.152 B-PP1X 54.2 114 70 B-PP2X 1.7 15— 72 96 — 30 Ex. 7 r-PPA 144.152 B-PP1Y 61.2 117 80 B-PP2X 1.7 15 — 7296 — 20 Ex. 8 r-PPB 145 B-PP1Y 61.2 117 70 B-PP2X 1.7 15 — 72 96 — 30

TABLE 2 Second resin layer First elastomer-modified First resin olefinbased resin Second elastomer-modified olefin based resin layer ContentContent Tmp ΔHc Tcp rate ΔHc1 ΔHc2 ΔHc Tcp1 Tcp2 Tcp rate Type (° C.)Type (J/g) (° C.) (mass %) Type (J/g) (J/g) (J/g) (° C.) (° C.) (° C.)(mass %) Com. Ex 7 r-PPA 144.152 B-PP1X 54.2 114 90 B-PP2V — — 40 — —108 10 Com. Ex 8 r-PPA 144.152 B-PP1X 54.2 114 99 EPR — — 11 — — 56 1Com. Ex. 9 r-PPA 144.152 B-PP1X 54.2 114 90 EPR — — 11 — — 56 10 Com.Ex. 10 r-PPA 144.152 B-PP1X 54.2 114 80 EPR — — 11 — — 56 20 Com. Ex. 11r-PPA 144.152 B-PP1X 54.2 114 70 EPR — — 11 — — 56 30 Ex. 9 r-PPA144.152 B-PP1X 54.2 114 90 B-PP2X 1.7 15 — 72 96 — 10

TABLE 3 Evaluation of presence or Seal degree of absence of strengthaggregation whitening at (N/15 mm of separation the time ofComprehensive width) interface shaping evaluation Com. Ex. 1 53 ◯ X XCom. Ex. 2 59 Δ Δ X Com. Ex. 3 44 Δ X X Ex. 1 47 ◯ ◯ ◯ Ex. 2 52 ◯ ⊚ ⊚Ex. 3 52 ◯ ⊚ ⊚ Com. Ex. 4 44 Δ X X Ex. 4 47 ◯ ◯ ◯ Com. Ex. 5 44 Δ X XCom. Ex. 6 45 Δ ◯ X Ex. 5 57 ◯ ◯ ◯ Ex. 6 60 ◯ ⊚ ⊚ Ex. 7 60 ◯ ⊚ ⊚ Ex. 858 ◯ ⊚ ⊚ Com. Ex. 7 56 Δ Δ X Com. Ex. 8 47 Δ X X Com. Ex. 9 49 X X XCom. Ex. 10 54 X X X Com. Ex. 11 56 X X X Ex. 9 45 ◯ ◯ ◯

Example 10

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 3.5 parts by weightof a first elastomer-modified olefin based resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g, 3.5 parts by weight of a second elastomer-modified olefinbased resin having a crystallization temperature of 96° C. and acrystallization energy of 15 J/g, and 1 parts by weight ofethylene-propylene random copolymer (Tmp: 144° C., 152° C.) at 210° C.Next, a resin composition was obtained by mixing 8 parts by weight ofthe first melt-kneaded product, 85.5 parts by weight of a firstelastomer-modified olefin resin having a crystallization temperature of114° C. or above and a crystallization energy of 54.2 J/g, and 9.5 partsby weight of a second elastomer-modified olefin based resin having acrystallization temperature of 88° C. or above and a crystallizationenergy of 14 J/g. A packaging material 1 for a power storage device wasobtained in the same manner as in Example 1 except that the second resinlayer 8 was constituted by using this resin composition.

Example 11

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 7 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, 1 partsby weight of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g, and 2 parts by weight of ethylene-propylene random copolymer (Tmp:144° C., 152° C.) at 210° C. Next, a resin composition was obtained bymixing 10 parts by weight of the first melt-kneaded product, 72 parts byweight of a first elastomer-modified olefin resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g, and 18 parts by weight of a second elastomer-modified olefinbased resin having a crystallization temperature of 96° C. above and acrystallization energy of 15 J/g. A packaging material 1 for a powerstorage device was obtained in the same manner as in Example 1 exceptthat the second resin layer 8 was constituted by using this resincomposition.

Example 12

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, 2 partsby weight of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g, and 4 parts by weight of ethylene-propylene random copolymer (Tmp:144° C., 152° C.) at 210° C. Next, a resin composition was obtained bymixing 20 parts by weight of the first melt-kneaded product, 64 parts byweight of a first elastomer-modified olefin resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g, and 16 parts by weight of a second elastomer-modified olefinbased resin having a crystallization temperature of 96° C. and acrystallization energy of 15 J/g. A packaging material 1 for a powerstorage device was obtained in the same manner as in Example 1 exceptthat the second resin layer 8 was constituted by using this resincomposition.

Example 13

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 21 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, 3 partsby weight of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g, and 6 parts by weight of ethylene-propylene random copolymer (Tmp:144° C., 152° C.) at 210° C. Next, a resin composition was obtained bymixing 30 parts by weight of the first melt-kneaded product, and 70parts by weight of a first elastomer-modified olefin resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g. A packaging material 1 for a power storage device was obtainedin the same manner as in Example 1 except that the second resin layer 8was constituted by using this resin composition.

Example 14

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 35 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, 5 partsby weight of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g, and 10 parts by weight of ethylene-propylene random copolymer (Tmp:144° C., 152° C.) at 210° C. Next, a resin composition was obtained bymixing 50 parts by weight of the first melt-kneaded product, and 50parts by weight of a first elastomer-modified olefin resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g. A packaging material 1 for a power storage device was obtainedin the same manner as in Example 1 except that the second resin layer 8was constituted by using this resin composition.

Example 15

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 21 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, 3 partsby weight of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g, and 3 parts by weight of ethylene-propylene random copolymer (Tmp:144° C., 152° C.) at 210° C. Next, a resin composition was obtained bymixing 30 parts by weight of the first melt-kneaded product, 56 parts byweight of a first elastomer-modified olefin resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g, and 14 parts by weight of a second elastomer-modified olefinbased resin having a crystallization temperature of 96° C. and acrystallization energy of 15 J/g. A packaging material 1 for a powerstorage device was obtained in the same manner as in Example 1 exceptthat the second resin layer 8 was constituted by using this resincomposition.

Example 16

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 8 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, and 2parts by weight of a second elastomer-modified olefin based resin havinga crystallization temperature of 96° C. and a crystallization energy of15 J/g at 210° C. Next, a resin composition was obtained by mixing 10parts by weight of the first melt-kneaded product, 72 parts by weight ofa first elastomer-modified olefin resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, and 18parts by weight of a second elastomer-modified olefin based resin havinga crystallization temperature of 96° C. above and a crystallizationenergy of 15 J/g. A packaging material 1 for a power storage device wasobtained in the same manner as in Example 1 except that the second resinlayer 8 was constituted by using this resin composition.

Example 17

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, 2 partsby weight of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g, and 2 parts by weight of ethylene-propylene random copolymer (Tmp:144° C., 152° C.) at 210° C. Next, a resin composition was obtained bymixing 20 parts by weight of the first melt-kneaded product, 64 parts byweight of a first elastomer-modified olefin resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g, and 16 parts by weight of a second elastomer-modified olefinbased resin having a crystallization temperature of 96° C. and acrystallization energy of 15 J/g. A packaging material 1 for a powerstorage device was obtained in the same manner as in Example 1 exceptthat the second resin layer 8 was constituted by using this resincomposition.

Example 18

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except for usinga resin composition obtained as described below as a resin compositionconstituting the second resin layer 8 and also using ethylene-propylenerandom copolymer (Tmp: 145° C.) as a resin composition constituting thefirst resin layer 7. Initially, a first melt-kneaded product wasobtained by mixing 16 parts by weight of ethylene-propylene randomcopolymer (Tmp: 144° C., 152° C.) and 4 parts by weight ofethylene-propylene rubber (EPR) and melt-kneaded at 210° C. Next, aresin composition was obtained by mixing 20 parts by weight of the firstmelt-kneaded product, 56 parts by weight of a first elastomer-modifiedolefin resin having a crystallization temperature of 117° C. or aboveand a crystallization energy of 61.2 J/g, and 24 parts by weight of asecond elastomer-modified olefin based resin having a crystallizationtemperature of 96° C. and a crystallization energy of 15 J/g. Using thisresin composition, a second resin layer 8 was constituted.

Example 19

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except for usinga resin composition obtained as described below as a resin compositionconstituting the second resin layer 8 and also using ethylene-propylenerandom copolymer (Tmp: 145° C.) as a resin composition constituting thefirst resin layer 7. Initially, a first melt-kneaded product wasobtained by mixing 14 parts by weight of homopolypropylene and 4 partsby weight of ethylene-1-butene rubber (EBR) and melt-kneading at 210° C.Next, a resin composition was obtained by mixing 20 parts by weight ofthe first melt-kneaded product, 56 parts by weight of a firstelastomer-modified olefin resin having a crystallization temperature of117° C. or above and a crystallization energy of 61.2 J/g, and 24 partsby weight of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g. Using this resin composition, a second resin layer 8 wasconstituted.

Example 20

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, and 6parts by weight of a second elastomer-modified olefin based resin havinga crystallization temperature of 96° C. and a crystallization energy of15 J/g at 210° C. Next, a resin composition was obtained by mixing 20parts by weight of the first melt-kneaded product, 64 parts by weight ofa first elastomer-modified olefin resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, and 16parts by weight of a second elastomer-modified olefin based resin havinga crystallization temperature of 96° C. and a crystallization energy of15 J/g. A packaging material 1 for a power storage device was obtainedin the same manner as in Example 1 except that the second resin layer 8was constituted by using this resin composition.

Example 21

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, and 6parts by weight of ethylene-propylene rubber (EPR) at 210° C. Next, aresin composition was obtained by mixing 20 parts by weight of the firstmelt-kneaded product, 64 parts by weight of a first elastomer-modifiedolefin resin having a crystallization temperature of 114° C. and acrystallization energy of 54.2 J/g, and 16 parts by weight of a secondelastomer-modified olefin based resin having a crystallizationtemperature of 96° C. and a crystallization energy of 15 J/g. Apackaging material 1 for a power storage device was obtained in the samemanner as in Example 1 except that the second resin layer 8 wasconstituted by using this resin composition.

Example 22

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, and 6parts by weight of styrene-ethylene-butylene-styrene copolymer (SEBS) at210° C. Next, a resin composition was obtained by mixing 20 parts byweight of the first melt-kneaded product, 64 parts by weight of a firstelastomer-modified olefin resin having a crystallization temperature of114° C. and a crystallization energy of 54.2 J/g, and 16 parts by weightof a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g. A packaging material 1 for a power storage device was obtained inthe same manner as in Example 1 except that the second resin layer 8 wasconstituted by using this resin composition.

Example 23

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofethylene-propylene random copolymer (Tmp: 144° C., 152° C.), and 6 partsby weight of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g at 210° C. Next, a resin composition was obtained by mixing 20 partsby weight of the first melt-kneaded product, 64 parts by weight of afirst elastomer-modified olefin resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, and 16parts by weight of a second elastomer-modified olefin based resin havinga crystallization temperature of 96° C. and a crystallization energy of15 J/g. A packaging material 1 for a power storage device was obtainedin the same manner as in Example 1 except that the second resin layer 8was constituted by using this resin composition.

Example 24

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by mixing 14 parts by weight ofethylene-propylene random copolymer (Tmp: 144° C., 152° C.) and 6 partsby weight of ethylene-1-butene rubber (EBR) and melt-kneaded at 210° C.Next, a resin composition was obtained by mixing 20 parts by weight ofthe first melt-kneaded product, 64 parts by weight of a firstelastomer-modified olefin resin having a crystallization temperature of114° C. and a crystallization energy of 54.2 J/g, and 16 parts by weightof a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g. A packaging material 1 for a power storage device was obtained inthe same manner as in Example 1 except that the second resin layer 8 wasconstituted by using this resin composition.

Example 25

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by mixing 14 parts by weight ofethylene-propylene random copolymer (Tmp: 144° C., 152° C.) and 6 partsby weight of styrene-ethylene-butylene-styrene copolymer (SEBS) andmelt-kneaded at 210° C. Next, a resin composition was obtained by mixing20 parts by weight of the first melt-kneaded product, 64 parts by weightof a first elastomer-modified olefin resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, and 16parts by weight of a second elastomer-modified olefin based resin havinga crystallization temperature of 96° C. and a crystallization energy of15 J/g. A packaging material 1 for a power storage device was obtainedin the same manner as in Example 1 except that the second resin layer 8was constituted by using this resin composition.

Example 26

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofhomopolypropylene, and 6 parts by weight of a second elastomer-modifiedolefin based resin having a crystallization temperature of 88° C. and acrystallization energy of 14 J/g at 210° C. Next, a resin compositionwas obtained by mixing 20 parts by weight of the first melt-kneadedproduct, 64 parts by weight of a first elastomer-modified olefin resinhaving a crystallization temperature of 114° C. and a crystallizationenergy of 54.2 J/g, and 16 parts by weight of a secondelastomer-modified olefin based resin having a crystallizationtemperature of 96° C. and a crystallization energy of 15 J/g. Apackaging material 1 for a power storage device was obtained in the samemanner as in Example 1 except that the second resin layer 8 wasconstituted by using this resin composition.

Example 27

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by mixing 14 parts by weight ofhomopolypropylene and 6 parts by weight of ethylene-propylene rubber(EPR) and melt-kneading at 210° C. Next, a resin composition wasobtained by mixing 20 parts by weight of the first melt-kneaded product,64 parts by weight of a first elastomer-modified olefin resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g, and 16 parts by weight of a second elastomer-modified olefinbased resin having a crystallization temperature of 96° C. and acrystallization energy of 15 J/g. A packaging material 1 for a powerstorage device was obtained in the same manner as in Example 1 exceptthat the second resin layer 8 was constituted by using this resincomposition.

Example 28

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by mixing 14 parts by weight ofhomopolypropylene and 6 parts by weight ofstyrene-ethylene-butylene-styrene copolymer (SEBS) and melt-kneading at210° C. Next, a resin composition was obtained by mixing 20 parts byweight of the first melt-kneaded product, 64 parts by weight of a firstelastomer-modified olefin resin having a crystallization temperature of114° C. and a crystallization energy of 54.2 J/g, and 16 parts by weightof a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g. A packaging material 1 for a power storage device was obtained inthe same manner as in Example 1 except that the second resin layer 8 wasconstituted by using this resin composition.

Example 29

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, and 6parts by weight of a second elastomer-modified olefin based resin havinga crystallization temperature of 96° C. and a crystallization energy of15 J/g at 210° C. Next, a resin composition was obtained by mixing 20parts by weight of the first melt-kneaded product, and 80 parts byweight of a first elastomer-modified olefin resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g. A packaging material 1 for a power storage device was obtainedin the same manner as in Example 1 except that the second resin layer 8was constituted by using this resin composition.

Example 30

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, and 6parts by weight of ethylene-propylene rubber (EPR) at 210° C. Next, aresin composition was obtained by mixing 20 parts by weight of the firstmelt-kneaded product, and 80 parts by weight of a firstelastomer-modified olefin resin having a crystallization temperature of114° C. and a crystallization energy of 54.2 J/g. A packaging material 1for a power storage device was obtained in the same manner as in Example1 except that the second resin layer 8 was constituted by using thisresin composition.

Example 31

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, and 6parts by weight of styrene-ethylene-butylene-styrene copolymer (SEBS) at210° C. Next, a resin composition was obtained by mixing 20 parts byweight of the first melt-kneaded product, and 80 parts by weight of afirst elastomer-modified olefin resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g. Apackaging material 1 for a power storage device was obtained in the samemanner as in Example 1 except that the second resin layer 8 wasconstituted by using this resin composition.

Example 32

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofethylene-propylene random copolymer (Tmp: 144° C., 152° C.), and 6 partsby weight of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g at 210° C. Next, a resin composition was obtained by mixing 20 partsby weight of the first melt-kneaded product, and 80 parts by weight of afirst elastomer-modified olefin resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g. Apackaging material 1 for a power storage device was obtained in the samemanner as in Example 1 except that the second resin layer 8 wasconstituted by using this resin composition.

Example 33

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by mixing 14 parts by weight ofethylene-propylene random copolymer (Tmp: 144° C., 152° C.) and 6 partsby weight of ethylene-1-butene rubber (EBR) and melt-kneaded at 210° C.Next, a resin composition was obtained by mixing 20 parts by weight ofthe first melt-kneaded product, and 80 parts by weight of a firstelastomer-modified olefin resin having a crystallization temperature of114° C. and a crystallization energy of 54.2 J/g. A packaging material 1for a power storage device was obtained in the same manner as in Example1 except that the second resin layer 8 was constituted by using thisresin composition.

Example 34

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by mixing 14 parts by weight ofethylene-propylene random copolymer (Tmp: 144° C., 152° C.) and 6 partsby weight of styrene-ethylene-butylene-styrene copolymer (SEBS) andmelt-kneaded at 210° C. Next, a resin composition was obtained by mixing20 parts by weight of the first melt-kneaded product, and 80 parts byweight of a first elastomer-modified olefin resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g. A packaging material 1 for a power storage device was obtainedin the same manner as in Example 1 except that the second resin layer 8was constituted by using this resin composition.

Example 35

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofhomopolypropylene, and 6 parts by weight of a second elastomer-modifiedolefin based resin having a crystallization temperature of 88° C. and acrystallization energy of 14 J/g at 210° C. Next, a resin compositionwas obtained by mixing 20 parts by weight of the first melt-kneadedproduct, and 80 parts by weight of a first elastomer-modified olefinresin having a crystallization temperature of 114° C. and acrystallization energy of 54.2 J/g. A packaging material 1 for a powerstorage device was obtained in the same manner as in Example 1 exceptthat the second resin layer 8 was constituted by using this resincomposition.

Example 36

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by mixing 14 parts by weight ofhomopolypropylene and 6 parts by weight of ethylene-propylene rubber(EPR) and melt-kneading at 210° C. Next, a resin composition wasobtained by mixing 20 parts by weight of the first melt-kneaded product,and 80 parts by weight of a first elastomer-modified olefin resin havinga crystallization temperature of 114° C. and a crystallization energy of54.2 J/g. A packaging material 1 for a power storage device was obtainedin the same manner as in Example 1 except that the second resin layer 8was constituted by using this resin composition.

Example 37

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 1, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by mixing 14 parts by weight ofhomopolypropylene and 6 parts by weight ofstyrene-ethylene-butylene-styrene copolymer (SEBS) and melt-kneading at210° C. Next, a resin composition was obtained by mixing 20 parts byweight of the first melt-kneaded product, and 80 parts by weight of afirst elastomer-modified olefin resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g. Apackaging material 1 for a power storage device was obtained in the samemanner as in Example 1 except that the second resin layer 8 wasconstituted by using this resin composition.

Comparative Example 12

A packaging material for a power storage device was obtained in the samemanner as in Example 12 except for using, as a resin constituting thefirst resin layer 7, a first elastomer-modified olefin based resinhaving a crystallization temperature of 114° C. and a crystallizationenergy of 54.2 J/g in place of ethylene-propylene random copolymer.

Comparative Example 13

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 12, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, 2 partsby weight of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g, and 4 parts by weight of ethylene-propylene random copolymer (Tmp:144° C., 152° C.) at 210° C. Next, a resin composition was obtained bymixing 20 parts by weight of the first melt-kneaded product, and 80parts by weight of a second elastomer-modified olefin resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g. A packaging material 1 for a power storage device was obtained inthe same manner as in Example 12 except that the second resin layer 8was constituted by using this resin composition.

Comparative Example 14

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 12, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, 2 partsby weight of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g, and 4 parts by weight of ethylene-propylene random copolymer (Tmp:144° C., 152° C.) at 210° C. Next, a resin composition was obtained bymixing 20 parts by weight of the first melt-kneaded product, 64 parts byweight of a first elastomer-modified olefin resin having acrystallization temperature of 96° C. and a crystallization energy of53.0 J/g, and 16 parts by weight of a second elastomer-modified olefinbased resin having a crystallization temperature of 96° C. and acrystallization energy of 15 J/g. A packaging material 1 for a powerstorage device was obtained in the same manner as in Example 12 exceptthat the second resin layer 8 was constituted by using this resincomposition.

Comparative Example 15

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 12, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, 2 partsby weight of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g, and 4 parts by weight of ethylene-propylene random copolymer (Tmp:144° C., 152° C.) at 210° C. Next, a resin composition was obtained bymixing 20 parts by weight of the first melt-kneaded product, 64 parts byweight of a first elastomer-modified olefin resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g, and 16 parts by weight of a second elastomer-modified olefinbased resin having a crystallization temperature of 83° C. and acrystallization energy of 10 J/g. A packaging material 1 for a powerstorage device was obtained in the same manner as in Example 12 exceptthat the second resin layer 8 was constituted by using this resincomposition.

Comparative Example 16

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 12, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, 2 partsby weight of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g, and 4 parts by weight of ethylene-propylene random copolymer (Tmp:144° C., 152° C.) at 210° C. Next, a resin composition was obtained bymixing 20 parts by weight of the first melt-kneaded product, 64 parts byweight of a first elastomer-modified olefin resin having acrystallization temperature of 106° C. and a crystallization energy of45.5 J/g, and 16 parts by weight of a second elastomer-modified olefinbased resin having a crystallization temperature of 96° C. and acrystallization energy of 15 J/g. A packaging material 1 for a powerstorage device was obtained in the same manner as in Example 12 exceptthat the second resin layer 8 was constituted by using this resincomposition.

Comparative Example 17

A packaging material 1 for a power storage device structured shown inFIG. 2 was obtained in the same manner as in Example 12, except forusing, as a resin composition constituting the second resin layer 8, aresin composition obtained as described below. Initially, a firstmelt-kneaded product was obtained by melt-kneading 14 parts by weight ofa first elastomer-modified olefin based resin having a crystallizationtemperature of 114° C. and a crystallization energy of 54.2 J/g, 2 partsby weight of a second elastomer-modified olefin based resin having acrystallization temperature of 96° C. and a crystallization energy of 15J/g, and 4 parts by weight of ethylene-propylene random copolymer (Tmp:144° C., 152° C.) at 210° C. Next, a resin composition was obtained bymixing 20 parts by weight of the first melt-kneaded product, 64 parts byweight of a first elastomer-modified olefin resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g, and 16 parts by weight of a second elastomer-modified olefinbased resin having a crystallization temperature of 108° C. and acrystallization energy of 40 J/g. A packaging material 1 for a powerstorage device was obtained in the same manner as in Example 12 exceptthat the second resin layer 8 was constituted by using this resincomposition.

Example 38

On both surfaces of an aluminum foil 4 having a thickness of 35 μm, achemical conversion treatment solution including phosphoric acid,polyacrylic acid (acrylic based resin), chromium (III) salt compound,water, and alcohol was applied, and then dried at 180° C. to form achemical conversion film. The chromium deposition amount of thischemical conversion film was 10 mg/m² per one surface.

Next, on one surface of the chemical conversion treated aluminum foil 4,a biaxially stretched 6 nylon film 2 having a thickness of 15 μm wad drylaminated (bonded) via a two-part curing type urethane based adhesive 5.

Next, a first melt-kneaded product was obtained by melt-kneading 14parts by weight of a first elastomer-modified olefin based resin havinga crystallization temperature of 114° C. and a crystallization energy of54.2 J/g, 2 parts by weight of a second elastomer-modified olefin basedresin having a crystallization temperature of 96° C. and acrystallization energy of 15 J/g, and 4 parts by weight ofethylene-propylene random copolymer (Tmp: 144° C., 152° C.) at 210° C.Next, a resin composition for a second resin layer was obtained bymixing 20 parts by weight of the first melt-kneaded product, 64 parts byweight of a first elastomer-modified olefin resin having acrystallization temperature of 114° C. and a crystallization energy of54.2 J/g, and 16 parts by weight of a second elastomer-modified olefinbased resin having a crystallization temperature of 96° C. and acrystallization energy of 15 J/g.

Next, a first resin layer 7 having a thickness of 8 μm and made of anethylene-propylene random copolymer and a second resin layer 8 having athickness of 22 μm (second resin layer 8 made of a resin composition forthe second resin layer) were co-extruded so that these layers arelaminated using a T die to obtain a sealant film 3 having a thickness of30 μm in which these two layers were laminated (first resin layer7/second resin layer 8) were obtained. Thereafter, one of surfaces ofthe first resin layer 7 of the sealant film 3 was overlapped on theother surface of the dry laminated aluminum foil 4 by a two-part curingtype maleic acid-modified polypropylene adhesive agent 6, and pinched byand between a rubber nip roll and a lamination roll heated to 100° C. tobe press-bonded and dry laminated. Thereafter, by performing aging(heating) at 50° C. for 5 days, a packaging material 1 for a powerstorage device having a structure shown in FIG. 1 was obtained.

As the two-part curing type maleic acid-modified polypropylene adhesiveagent, using an adhesive agent solution in which 100 parts by weight ofmaleic acid-modified polypropylene (melting point 80° C., acid value 10mgKOH/g) as a base resin, 8 parts by weight of hexamethylenediisocyanate isocyanurate (NCO content rate: 20 mass %) as a curingagent, and further a solvent were mixed, the adhesive agent solution wasapplied on the other surface of the aluminum foil 4 so that the solidcontent applied amount became 2 g/m², and heated and dried, and thenoverlapped on one of surfaces of the first resin layer 7 of the sealantfilm 3.

In Examples 10 to 38 and Comparative Examples 12 to 17, melt-kneadingwas performed by using a 40φ extruder (L/D=24) equipped with a screwwith tip Dulmage and a strand forming die at 210° C., and the formedstrand was water-cooled and solidified in a water tank and cut with acutter. Thus, a pellet (granular shape having a major axis of 4 mm to 5mm) of a first melt-kneaded product was obtained.

TABLE 4 Second resin layer First elastomer-modified olefin based resinSecond elastomer-modified olefin based resin Mixed Mixed First Firstresin amount amount melt-kneaded layer (parts (parts product Tmp ΔHc Tcpby ΔHc1 ΔHc2 ΔHc Tcp1 Tcp2 Tcp by Type (parts by Type (° C.) Type (J/g)(° C.) weight) Type (J/g) (J/g) (J/g) (° C.) (° C.) (° C.) weight)weight) Ex. 10 r-PPA 144.152 B-PP1X 54.2 114 85.5 B-PP2Y — — 14 — —  889.5 B-PP1X(3.5)/B- PP2X(3.5)/r-PPA(1) Ex. 11 r-PPA 144.152 B-PP1X 54.2114 72 B-PP2X 1.7 15 — 72 96 — 18 B-PP1X(7)/B- PP2X(1)/r-PPA(2) Ex. 12r-PPA 144.152 B-PP1X 54.2 114 64 B-PP2X 1.7 15 — 72 96 — 16B-PP1X(14)/B- PP2X(2)/r-PPA(4) Ex. 13 r-PPA 144.152 B-PP1X 54.2 114 70 —— — — — — — — B-PP1X(21)/B- PP2X(3)/r-PPA(6) Ex. 14 r-PPA 144.152 B-PP1X54.2 114 50 — — — — — — — — B-PP1X(35)/B- PP2X(5)/r-PPA(10) Ex. 15 r-PPA144.152 B-PP1X 54.2 114 56 B-PP2X 1.7 15 — 72 96 144 14 B-PP1X(21)/B-PP2X(3)/r- PPA(3)/homePP(3) Ex. 16 r-PPA 144.152 B-PP1X 54.2 114 72B-PP2X 1.7 15 — 72 96 144 18 B-PP1X(8)/B-PP2X(2) Ex. 17 r-PPA 144.152B-PP1X 54.2 114 64 B-PP2X 1.7 15 — 72 96 144 16 B-PP1X(14)/B- PP2X(2)/r-PPA(2)/EPR(2) Ex. 18 r-PPB 145 B-PP1Y 61.2 117 56 B-PP2X 1.7 15 — 72 96144 24 r-PPA(16)/EPR(4) Ex. 19 r-PPB 145 B-PP1Y 61.2 117 56 B-PP2X 1.715 — 72 96 144 24 HomoPP(14)/EBR(6)

TABLE 5 Second resin layer First elastomer-modified olefin based resinSecond elastomer-modified olefin based resin Mixed Mixed First Firstresin amount amount melt-kneaded layer (parts (parts product Tmp ΔHc Tcpby ΔHc1 ΔHc2 ΔHc Tcp1 Tcp2 Tcp by Type (parts by Type (° C.) Type (J/g)(° C.) weight) Type (J/g) (J/g) (J/g) (° C.) (° C.) (° C.) weight)weight) Ex. 20 r-PPA 144.152 B-PP1X 54.2 114 64 B-PP2X 1.7 15 — 72 96 —16 B-PP1X(14)/B-PP2X(6) Ex. 21 r-PPA 144.152 B-PP1X 54.2 114 64 B-PP2X1.7 15 — 72 96 — 16 B-PP1X(14)/EPR(6) Ex. 22 r-PPA 144.152 B-PP1X 54.2114 64 B-PP2X 1.7 15 — 72 96 — 16 B-PP1X(14)/SEBS(6) Ex. 23 r-PPA144.152 B-PP1X 54.2 114 64 B-PP2X 1.7 15 — 72 96 — 16r-PPA(14)/B-PP2X(6) Ex. 24 r-PPA 144.152 B-PP1X 54.2 114 64 B-PP2X 1.715 — 72 96 — 16 r-PPA(14)/EBR(6) Ex. 25 r-PPA 144.152 B-PP1X 54.2 114 64B-PP2X 1.7 15 — 72 96 — 16 r-PPA(14)/SEBS(6) Ex. 26 r-PPA 144.152 B-PP1X54.2 114 64 B-PP2X 1.7 15 — 72 96 — 16 HomoPP(14)/B-PP2Y(6) Ex. 27 r-PPA144.152 B-PP1X 54.2 114 64 B-PP2X 1.7 15 — 72 96 — 16 HomoPP(14)/EPR(6)Ex. 28 r-PPA 144.152 B-PP1X 54.2 114 64 B-PP2X 1.7 15 — 72 96 — 16HomoPP(14)/SEBS(6) Ex. 38 r-PPA 144.152 B-PP1X 54.2 114 64 B-PP2X 1.7 15— 72 96 — 16 B-PP1X(14)/B- PP2X(2)/r-PPA(4)

TABLE 6 Second resin layer First elastomer-modified olefin based resinSecond elastomer-modified olefin based resin Mixed Mixed First Firstresin amount amount melt-kneaded layer (parts (parts product Tmp ΔHc Tcpby ΔHc Tcp by Type (parts by Type (° C.) Type (J/g) (° C.) weight) Type(J/g) (° C.) weight) weight) Ex. 29 r-PPA 144.152 B-PP1X 54.2 114 80 — —— — B-PP1X(14)/B-PP2X(6) Ex. 30 r-PPA 144.152 B-PP1X 54.2 114 80 — — — —B-PP1X(14)/EPR(6) Ex. 31 r-PPA 144.152 B-PP1X 54.2 114 80 — — — —B-PP1X(14)/SEBS(6) Ex. 32 r-PPA 144.152 B-PP1X 54.2 114 80 — — — —r-PPA(14)/B-PP2X(6) Ex. 33 r-PPA 144.152 B-PP1X 54.2 114 80 — — — —r-PPA(14)/EBR(6) Ex. 34 r-PPA 144.152 B-PP1X 54.2 114 80 — — — —r-PPA(14)/SEBS(6) Ex. 35 r-PPA 144.152 B-PP1X 54.2 114 80 — — — —HomoPP(14)/BPP2Y(6) Ex. 36 r-PPA 144.152 B-PP1X 54.2 114 80 — — — —HomoPP(14)/EPR(6) Ex. 37 r-PPA 144.152 B-PP1X 54.2 114 80 — — — —HomoPP(14)/SEBS(6)

TABLE 7 Second resin layer First elastomer-modified olefin based resinSecond elastomer-modified olefin based resin Mixed Mixed First Firstresin amount amount melt-kneaded layer (parts (parts product Tmp ΔHc Tcpby ΔHc1 ΔHc2 ΔHc Tcp1 Tcp2 Tcp by Type (parts by Type (° C.) Type (J/g)(° C.) weight) Type (J/g) (J/g) (J/g) (° C.) (° C.) (° C.) weight)weight) Com. Ex. 12 B-PP1X — B-PP1X 54.2 114 64 B-PP2X 1.7 15 — 72 96 —16 B-PP1X(14)/B- PP2X(2)/r-PPA(4) Com. Ex. 13 r-PPA 144.152 — — — —B-PP2X 1.7 15 — 72 96 — 80 B-PP1X(14)/B- PP2X(2)/r-PPA(4) Com. Ex. 14r-PPA 144.152 B-PP1V 53.0 96 64 B-PP2X 1.7 15 — 72 96 — 16 B-PP1X(14)/B-PP2X(2)/r-PPA(4) Com. Ex. 15 r-PPA 144.152 B-PP1X 54.2 114 64 B-PP2Z — —10 — — 83 16 B-PP1X(14)/B- PP2X(2)/r-PPA(4) Com. Ex. 16 r-PPA 144.152B-PP1W 45.5 106 64 B-PP2X 1.7 15 — 72 96 — 16 B-PP1X(14)/B-PP2X(2)/r-PPA(4) Com. Ex. 17 r-PPA 144.152 B-PP1X 54.2 114 64 B-PP2V — —40 — — 108 16 B-PP1X(14)/B- PP2X(2)/r-PPA(4)

TABLE 8 Evaluation Presence or Seal of cohesion absence of strengthdegree at whitening at (N/15 mm separation the time of Comprehensivewidth) interface shaping evaluation Ex. 10 56 ⊚ ⊚ ⊚ Ex. 11 54 ⊚ ⊚ ⊚ Ex.12 56 ⊚ ⊚ ⊚ Ex. 13 61 ⊚ ⊚ ⊚ Ex. 14 61 ⊚ ⊚ ⊚ Ex. 15 54 ⊚ ⊚ ⊚ Ex. 16 55 ⊚⊚ ⊚ Ex. 17 51 ⊚ ⊚ ⊚ Ex. 18 56 ⊚ ⊚ ⊚ Ex. 19 54 ⊚ ⊚ ⊚ Ex. 20 54 ⊚ ⊚ ⊚ Ex.21 51 ⊚ ⊚ ⊚ Ex. 22 44 ⊚ ◯ ⊚ Ex. 23 49 ⊚ ⊚ ⊚ Ex. 24 51 ⊚ ⊚ ⊚ Ex. 25 46 ⊚◯ ⊚ Ex. 26 51 ⊚ ⊚ ⊚ Ex. 27 50 ⊚ ⊚ ⊚ Ex. 28 46 ⊚ ◯ ⊚

TABLE 9 Evaluation Presence or Seal of cohesion absence of strengthdegree at whitening at (N/15 mm separation the time of Comprehensivewidth) interface shaping evaluation Ex. 29 51 ⊚ ⊚ ⊚ Ex. 30 51 ⊚ ⊚ ⊚ Ex.31 46 ⊚ ◯ ⊚ Ex. 32 50 ⊚ ⊚ ⊚ Ex. 33 49 ⊚ ⊚ ⊚ Ex. 34 46 ⊚ ◯ ⊚ Ex. 35 45 ⊚⊚ ⊚ Ex. 36 51 ⊚ ⊚ ⊚ Ex. 37 44 ⊚ ◯ ⊚ Ex. 38 56 ⊚ ⊚ ⊚ Com. Ex. 12 53 ◯ Δ XCom. Ex. 13 56 Δ Δ X Com. Ex. 14 44 ◯ Δ X Com. Ex. 15 46 Δ Δ X Com. Ex.16 45 Δ ◯ X Com. Ex. 17 55 ◯ Δ X

In Examples 1 to 9 and Comparative Examples 1 to 11, the firstelastomer-modified olefin based resin was made of EPR-modifiedhomopolypropylene and an EPR-modified product of ethylene-propylenerandom copolymer, and the second elastomer-modified olefin based resinwas made of EPR-modified homopolypropylene and an EPR-modified productof ethylene-propylene random copolymer. The EPR denotesethylene-propylene rubber.

Further, in Examples 10 to 38 and Comparative Examples 12 to 17, thefirst elastomer-modified olefin based resin was made of EPR-modifiedhomopolypropylene and an EPR-modified product of ethylene-propylenerandom copolymer, and the second elastomer-modified olefin based resinwas made of EPR-modified homopolypropylene and an EPR-modified productof ethylene-propylene random copolymer. The EPR denotesethylene-propylene rubber.

In Tables 1 to 7, the following abbreviations showing first and secondelastomer-modified olefin based resins denote the following resins.

“B-PP1X”—first elastomer-modified olefin based resin having acrystallization temperature (Tcp) of 114° C. and a crystallizationenergy (ΔHc) of 54.2 J/g

“B-PP1Y”—first elastomer-modified olefin based resin having acrystallization temperature (Tcp) of 117° C. and a crystallizationenergy (ΔHc) of 61.2 J/g

“B-PP1Z”—first elastomer-modified olefin based resin having acrystallization temperature (Tcp) of 106° C. and a crystallizationenergy (ΔHc) of 54.0 J/g

“B-PP1V”—first elastomer-modified olefin based resin having acrystallization temperature (Tcp) of 96° C. and a crystallization energy(ΔHc) of 53.0 J/g

“B-PP1W”—first elastomer-modified olefin based resin having acrystallization temperature (Tcp) of 106° C. and a crystallizationenergy (ΔHc) of 45.5 J/g

“B-PP2X”—second elastomer-modified olefin based resin having acrystallization temperature (Tcp) of 96° C. and a crystallization energy(ΔHc) of 15 J/g

“B-PP2Y”—second elastomer-modified olefin based resin having acrystallization temperature (Tcp) of 88° C. and a crystallization energy(ΔHc) of 14 J/g

“B-PP2Z”—second elastomer-modified olefin based resin having acrystallization temperature (Tcp) of 83° C. and a crystallization energy(ΔHc) of 10 J/g

“B-PP2V”—second elastomer-modified olefin based resin having acrystallization temperature (Tcp) of 108° C. and a crystallizationenergy (ΔHc) of 40 J/g

Further, in Tables, the following abbreviations denote the followingresins, respectively.

“EPR”—ethylene-propylene rubber

“EBR”—ethylene-1-butene rubber

“SEBS”—styrene-ethylene-butylene-styrene copolymer

“homo PP”—homopolypropylene

“r-PPA”—ethylene-propylene random copolymer (melting point Tmp: 144° C.,152° C.)

“r-PPB”—ethylene-propylene random copolymer (melting point Tmp: 145°C.).

The “crystallization temperature” of each of the aforementioned resinswas a crystallization peak temperature (Tcp) measured by differentialscanning calorimetry (DSC) in accordance with JIS K7121-1987. Further,the “crystallization energy” of each of the aforementioned resins was acrystallization energy (ΔHc) measured by differential scanningcalorimetry (DSC) in accordance with JIS K7122-1987. Both of them weremeasured by the following Measurement conditions.

Temperature raising and lowering speed: temperature raising and loweringrate at 10° C./min between 23° C. to 210° C.

Sample amount: 5 mg was metered

Container: aluminum pan was used

Apparatus: “DSC-60A” manufactured by Shimadzu Corporation

With regard to “crystallization energy”, when there exists only onecrystallization peak, “crystallization energy” is shown as “ΔHc”, andwhen there exist two crystallization peaks, “crystallization energy” ofthe crystallization peak lower in temperature is shown as “ΔHc1”. The“crystallization energy” of the crystallization peak higher intemperature is shown as “ΔHc2”.

Further, with regard to “crystallization temperature”, when there existsonly one crystallization peak, “crystallization temperature” is shown as“Tcp”, and when there exist two crystallization peaks, “crystallizationtemperature” lower in temperature is shown as “Tcp1”. The“crystallization temperature” higher in temperature is shown as “Tcp2”.

As to each packaging material for a power storage device obtained asdescribed above, based on the following measurement method andevaluation method, the seal strength was measured, the cohesion degreeof the separation interface when separated was evaluated, and thepresence or absence of whitening at the time of shaping was evaluated.

<Seal Strength Measurement Method>

From the obtained packaging material, two test pieces each having awidth of 15 mm and a length of 150 mm were cut. Thereafter, these testpieces were heat sealed by single-sided heating under the conditions ofheat seal temperature: 200° C., sealing pressure: 0.2 MPa (gauge displaypressure), and sealing time: 2 seconds using a heat sealing device(TP-701-A) manufactured by Tester Sangyo Co., Ltd. in a state in whichthe two test pieces are overlapped with the inner sealant layers and incontact with each other.

Next, as to a pair of packaging materials with the inner sealant layersheat-sealed joined as described above, using a Strograph (AGS-5kNX)manufactured by Shimadzu Corporation in accordance with JIS Z0238-1998,the separation strength when the packaging materials (test pieces) wereseparated at the sealed portions of the inner sealant layers by 90degrees at a tensile rate of 100 mm/min was measured, and set as theseal strength (N/15 mm width).

When this seal strength was 30 N/15 mm width or more, it was evaluatedas “Pass”. It is preferable that the seal strength is 40 N/15 mm widthor more.

<Evaluation Method of Cohesion Degree of Separation Interface>

Both surfaces of the separated portions (broken portions) of the innersealant layers of the packaging material that the seal strength(separation strength) was measured were visually observed, the presenceor absence or degree (it can be judged that the stronger the whiteningis, the larger the cohesion degree) of whitening of both surfaces of theseparated portion (broken portion) was evaluated based on the followingJudgment criteria.

(Judgment Criteria)

It was denoted as “X” when whitening was not recognized or there wasalmost no whitening and the cohesion degree was low.

It was denoted as “Δ” when whitening was generated to some extent andthe cohesion degree was medium.

It was denoted as “◯” when whitening was generated markedly and thecohesion degree was large.

It was denoted as “⊚” when whitening was generated further markedly andthe cohesion degree was further large.

<Evaluation Method of the Presence or Absence of Whitening at the Timeof Shaping>

Using a deep drawing tool manufactured by Amada Co., Ltd., the packagingmaterial was deep drawn into a rectangular shape having a depth of 5 mmunder the following shaping condition. Thereafter, the inner sidesurface (three inner sealant layer surfaces) of the accommodation recessof the obtained formed product was visually observed and the presence orabsence or the degree of whitening was evaluated based on the followingjudgment criteria.

(Judgment Criteria)

The formed product after the shaping was visually observed, and it wasevaluated as “⊚” when no whitening was recognized or almost notrecognized, “◯” when there was less whitening, and “Δ” when whiteningwas generated to some extent, and “X” when whitening was generatedmarkedly.

(Shaping Condition)

shaping die—punch: 33.3 mm×53.9 mm, die: 80 mm×120 mm, corner R: 2 mm,punch R: 1.3 mm, die R: 1 mm

wrinkle pressing pressure—gauge pressure: 0.475 MPa, actual pressure(calculated value): 0.7 MPa

material—SC (carbon steel) material, only punch R was chrome-plated

<Comprehensive Evaluation>

By comprehensively determining, the aforementioned three evaluationresults were evaluated in four stages, when the comprehensive evaluationwas especially excellent, it was evaluated as “⊚”, when thecomprehensive evaluation was excellent, it was evaluated as “◯”, whenthe comprehensive evaluation was somewhat poor, it was evaluated as “Δ”,and when the comprehensive evaluation was poor, it was evaluated as “X”.

Apparent from Table, the packaging material for a power storage device(packaging material for a power storage device using the sealant film ofthe present invention) of Examples 1 to 9 of the present invention hadadequate seal strength and the degree of whitening at the separationinterface was large. Therefore, the cohesion degree of the separationinterface was high and cohesive failure was generated inside of thesealant layer at the time of separation, and further whitening at thetime of shaping was also suppressed. As described above, in the case ofusing a packaging material for a power storage device of Examples 1 to 9of the present invention, cohesive failure was generated inside thesealant layer. Therefore, separation unlikely occurs at the interface ofthe metal foil layer 4 and the inner sealant layer 3 at the time ofseparation (breakage). Thus, when a separation point (broken point) forbursting prevention occurs, there is a merit that a breakage continuingfrom the separation point (broken point) as a starting point unlikelyprogresses.

On the other hand, in Comparative Examples 1 to 11 deviated from thedefined range of claims of the present invention, all of thecomprehensive evaluations were “X”.

Apparent from Table, the packaging material for a power storage device(packaging material for a power storage device using the sealant film ofthe present invention) of Examples 10 to 38 of the present invention hadadequate seal strength and the degree of whitening at the separationinterface was adequately large. Therefore, the cohesion degree of theseparation interface was high and cohesive failure was generated insideof the sealant layer at the time of separation, and further whitening atthe time of shaping was also adequately suppressed. As described above,in the case of using a packaging material for a power storage device ofExamples 10 to 38 of the present invention, cohesive failure wasgenerated inside the sealant layer. Therefore, separation unlikelyoccurs at the interface of the metal foil layer 4 and the inner sealantlayer 3 at the time of separation (breakage). Thus, when a separationpoint (broken point) for bursting prevention occurs, there is a meritthat a breakage continuing from the separation point (broken point) as astarting point unlikely progresses.

On the other hand, in Comparative Examples 12 to 17 deviated from thedefined range of claims of the present invention, all of thecomprehensive evaluations were “X”.

INDUSTRIAL APPLICABILITY

The sealant film for a packaging material of a power storage deviceaccording to the present invention can be used as a sealant film for apackaging material of a power storage device, such as, e.g., mobilestorage batteries, automotive storage batteries, regenerative energyrecovering storage batteries, condensers (capacitors), andall-solid-state batteries.

The packaging material for a power storage device according to thepresent invention can be used as a packaging material for, e.g., mobilestorage batteries, automotive storage batteries, regenerative energyrecovering storage batteries, condensers (capacitors), andall-solid-state batteries.

The power storage device according to the present invention can be usedas mobile storage batteries, automotive storage batteries, regenerativeenergy recovering storage batteries, condensers (capacitors), andall-solid-state batteries.

It should be understood that the terms and expressions used herein areused for explanation and have no intention to be used to construe in alimited manner, do not eliminate any equivalents of features shown andmentioned herein, and allow various modifications falling within theclaimed scope of the present invention.

While the present invention may be embodied in many different forms, anumber of illustrative embodiments are described herein with theunderstanding that the present disclosure is to be considered asproviding examples of the principles of the invention and such examplesare not intended to limit the invention to preferred embodimentsdescribed herein and/or illustrated herein.

While illustrative embodiments of the invention have been describedherein, the present invention is not limited to the various preferredembodiments described herein, but includes any and all embodimentshaving equivalent elements, modifications, omissions, combinations(e.g., of aspects across various embodiments), adaptations and/oralterations as would be appreciated by those in the art based on thepresent disclosure. The limitations in the claims are to be interpretedbroadly based on the language employed in the claims and not limited toexamples described in the present specification or during theprosecution of the application, which examples are to be construed asnon-exclusive.

DESCRIPTION OF THE SYMBOLS

-   1 packaging material for a power storage device-   2 base material layer (outer layer)-   3 inner sealant layer (sealant film)-   4 metal foil layer-   7 first resin layer-   8 second resin layer-   10 packaging case for a power storage device (shaped product)-   15 packaging member-   30 power storage device-   31 power storage device main body

The invention claimed is:
 1. A sealant film for a packaging material ofa power storage device, comprising: a laminated body of two or morelayers, wherein the laminated body includes a first resin layercontaining 50 mass % or more of a random copolymer containing propyleneand another copolymer component other than propylene as copolymercomponents, a second resin layer formed by a mixed resin containing afirst elastomer-modified olefin based resin having a crystallizationtemperature of 105° C. or higher and a crystallization energy of 50 J/gor more, and a second elastomer-modified olefin based resin having acrystallization temperature is 85° C. or higher and a crystallizationenergy of 30 J/g or less, wherein the first elastomer-modified olefinbased resin is made of elastomer-modified homopolypropylene and/orelastomer-modified random copolymer, wherein the secondelastomer-modified olefin based resin is made of elastomer-modifiedhomopolypropylene and/or elastomer-modified random copolymer, whereinthe elastomer-modified random copolymer is an elastomer-modified productof a random copolymer containing propylene and another copolymercomponent other than propylene as copolymer components, and wherein inthe second resin layer, a total value of a content rate of the firstelastomer-modified olefin based resin and a content rate of the secondelastomer-modified olefin based resin is 50 mass % or more.
 2. Thesealant film for a packaging material of a power storage device asrecited in claim 1, wherein in the second resin layer, the content rateof the second elastomer-modified olefin based resin is 1 mass % to 50mass %.
 3. The sealant film for a packaging material of a power storagedevice as recited in claim 1, wherein the elastomer in theelastomer-modified homopolypropylene and/or elastomer-modified randomcopolymer in the first and/or second elastomer-modified olefin is anethylene-propylene rubber.
 4. The sealant film for a packaging materialof a power storage device as recited in claim 1, wherein the first resinlayer contains an anti-blocking agent and a slip agent together with therandom copolymer, and wherein the second resin layer contains a slipagent together with the first elastomer-modified olefin based resin andthe second elastomer-modified olefin based resin.
 5. The sealant filmfor a packaging material of a power storage device as recited in claim1, wherein the second elastomer-modified olefin based resin has two ormore crystallization peaks in a DSC measurement graph.
 6. The sealantfilm for a packaging material of a power storage device as recited inclaim 1, wherein the sealant film comprises only the first resin layerand the second resin layer laminated on one surface of the first resinlayer.
 7. The sealant film for a packaging material of a power storagedevice as recited in claim 1, wherein the sealant film is a laminatedbody in which at least three layers are laminated, the at least threelayers including the second resin layer, the first resin layer laminatedon one of surfaces of the second resin layer, and a first resin layerlaminated on the other of surfaces of the second resin layer.
 8. Apackaging material for a power storage device, comprising: a basematerial layer as an outer layer; an inner sealant layer made of thesealant film as recited in claim 1; and a metal foil layer arrangedbetween the base material layer and the inner sealant layer, wherein inthe inner sealant layer, the first resin layer is arranged on aninnermost layer side.
 9. A sealant film for a packaging material of apower storage device, comprising: a laminated body of two or more layersincluding a first resin layer containing 50 mass % or more of a randomcopolymer containing propylene and another copolymer component otherthan propylene as copolymer components, a second resin layer formed by acomposition containing a first elastomer-modified olefin based resinhaving a crystallization temperature of 105° C. or higher and acrystallization energy of 50 J/g or more, and a polymer component,wherein the first elastomer-modified olefin based resin is made ofelastomer-modified homopolypropylene and/or elastomer-modified randomcopolymer, wherein the elastomer-modified random copolymer is anelastomer-modified product of a random copolymer containing propyleneand another copolymer component other than propylene as copolymercomponents, wherein in the second resin layer, a content rate of thefirst elastomer-modified olefin based resin is 50 mass % or more, andwherein the polymer component is at least one kind of polymer componentsselected from the group consisting of a random copolymer containingpropylene and another copolymer component other than propylene ascopolymer components, homopolypropylene, olefin based elastomer andstyrene based elastomer.
 10. The sealant film for a packaging materialof a power storage device as recited in claim 9, wherein in the secondresin layer, a content rate of the polymer component is 1 mass % or moreand less than 50 mass %.
 11. The sealant film for a packaging materialof a power storage device as recited in claim 9, wherein an elastomer inthe elastomer-modified homopolypropylene is an ethylene-propylenerubber, and wherein an elastomer in the elastomer-modified randomcopolymer is an ethylene-propylene rubber.
 12. The sealant film for apackaging material of a power storage device as recited in claim 9,wherein the first resin layer contains an anti-blocking agent and a slipagent, and wherein the second resin layer further contains a slip agent.13. The sealant film for a packaging material of a power storage deviceas recited in claim 9, wherein the sealant film comprises only the firstresin layer and the second resin layer laminated on one surface of thefirst resin layer.
 14. The sealant film for a packaging material of apower storage device as recited in claim 9, wherein the sealant film isa laminated body in which at least three layers are laminated, the atleast three layers including the second resin layer, a first resin layerlaminated on one of surfaces of the second resin layer, and a firstresin layer laminated on the other of surfaces of the second resinlayer.
 15. A packaging material for a power storage device, comprising:a base material layer as an outer layer; an inner sealant layer made ofthe sealant film as recited in claim 9; and a metal foil layer arrangedbetween the base material layer and the inner sealant layer, wherein inthe inner sealant layer, the first resin layer is arranged on aninnermost layer side.
 16. A sealant film for a packaging material of apower storage device, comprising: a laminated body of two or morelayers, wherein the laminated body includes a first resin layercontaining 50 mass % or more of a random copolymer containing propyleneand another copolymer component other than propylene as copolymercomponents, a second resin layer formed by a composition containing afirst elastomer-modified olefin based resin having a crystallizationtemperature of 105° C. or higher and a crystallization energy of 50 J/gor more, a second elastomer-modified olefin based resin having acrystallization temperature of 85° C. or higher and a crystallizationenergy of 30 J/g or less, and a polymer component, wherein the firstelastomer-modified olefin based resin is made of elastomer-modifiedhomopolypropylene and/or elastomer-modified random copolymer, whereinthe second elastomer-modified olefin based resin is made ofelastomer-modified homopolypropylene and/or elastomer-modified randomcopolymer, wherein the elastomer-modified random copolymer is anelastomer-modified product of a random copolymer containing propyleneand another copolymer component other than propylene as copolymercomponents, wherein in the second resin layer, a total value of acontent rate of the first elastomer-modified olefin based resin and acontent rate of the second elastomer-modified olefin based resin is 50mass % or more, and wherein the polymer component is at least one kindof polymer component selected from the group consisting of a randomcopolymer containing propylene and another copolymer component otherthan propylene as copolymer components, homopolypropylene, olefin basedelastomer and styrene based elastomer.
 17. The sealant film for apackaging material of a power storage device as recited in claim 16,wherein in the second resin layer, a content rate of the secondelastomer-modified olefin based resin is 1 mass % to 50 mass %.
 18. Thesealant film for a packaging material of a power storage device asrecited in claim 16, wherein the second elastomer-modified olefin basedresin has two or more crystallization peaks in a DSC measurement graph.